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DISEASES  OF  THE  EYE 


OPHTHALMOSCOPY 


A  HANDBOOK  FOR  PHYSICIANS  AND  STUDENTS 


BY 

DR.  A.   EUGEN   PICK 

UNIVERSITY   OF   ZURICH 

AUTHORIZED    TRANSLATION 

BY 

ALBERT  B.  HALE,  A.B.,  M.D. 

ONE   OF  THE   OPHTHALMIC   SURGEONS  TO  THE   UNITED   HEBREW  CHARITIES;    CONSULTING  OPHTHALMIC 

SURGEON    TO    CHARITY    HOSPITAL,    CHICAGO;      LATE    VOL.    ASST.    IMPERIAL 

EYE    CLINIC,    UNIVERSITY    OF    KIEL 


WITH    A    GLOSSARY    AND     158    ILLUSTRATIONS 
MANY  OF  WHICH  ARE  PRINTED  IN  COLORS 


PHILADELPHIA 

P.    BLAKISTON,   SON    &    CO. 

IOI2     WALNUT     STREET 
I  896 


Copyright,  1896,  by  P.  Blakiston,  Son  &  Co. 


PRESS  OF  WM.  F.  FELL  A  CO., 

1220-2*  sansom  Street, 

philadelphia. 


iuUj 


PREFACE. 


He  who  writes  a  book  is  accustomed  to  make  apology  for  him- 
self in  the  preface.  To  this  justly  beloved  custom  I  also  yield, 
and,  for  my  own  apology,  I  wish  to  say  that  our  best  text-books 
of  ophthalmology  are  too  exhaustive;  at  least,  this  complaint  is 
not  seldom  heard  from  the  pupil  to  whom  their  purchase  is  sug- 
gested. So  it  seems  that  for  a  compactly  written  book,  in  spite  of 
the  number  of  others  already  at  hand,  there  is  still  a  place. 

A  text-book  may  be  short  and  yet  complete  only  at  a  sacrifice 
of  some  detail;  the  author  should,  perhaps,  confine  himself  to  a  dry 
narrative  of  facts  and  rules ;  but  to  write  such  a  book  would  cer- 
tainly be  no  pleasure  to  me.  I  imagine  rather  a  book  that  would 
present  the  connection  of  things,  the  whys  and  the  wherefores. 
Something  must  be  left  out,  however,  and,  in  deciding  on  this 
something,  I  concluded  that  pathological  statements  or  hypotheses 
should  receive  mention  only  so  far  as  they  were  necessary  for  illus- 
tration of  diseased  conditions  ;  and,  further,  that  a  text-book  could 
not  replace  but  could  only  supplement  the  clinical  study  of  diseases 
and  operations  and  the  uses  of  the  ophthalmoscope,  and  that  a 
merely  introductory  idea  of  many  subjects  must  be  sufficient.  I 
have  omitted  authorities,  since  a  complete  list  would  be  too  heavy 
a  ballast,  and  an  incomplete  one,  as  often  seen — half  a  dozen  brack- 
etted  names  after  a  statement, — is  certainly,  at  least  for  the  reader, 
without  value.  Only  when  a  name  came  unbidden  to  my  pen  or 
needed  mention  as  a  voucher  for  accuracy,  have  I  woven  it  in. 

To  make  the  book  easier  for  the  reader  I  have  used  a  goodly 
number  of  colored  illustrations  and  have  introduced  them  into  the 
text ;  this  was  a  difficult  matter,  and  the  reader  will  probably  under- 
stand why  I  have  not  been  altogether  successful  in  reproducing  the 
exact  colors  with  perfect  accuracy. 

vii 


Vlll  PREFACE. 

[In  writing  the  book,  I  had  a  particular  pleasure  in  omitting  super- 
fluous words ;  but  I  was  soon  obliged  to  decide  to  put  many  of 
them  back  again  in  order  to  make  the  sense  clear.  Generally- 
speaking,  therefore,  I  have  used  only  those  Germanized  words 
which  Hirschberg  and  other  friends  of  ophthalmological  purity  of 
speech  have  authorized.  (This  refers,  of  course,  to  the  German 
edition. — Translator).] 

A.  E.  Pick. 

ZOrich,  June,   i8g4. 


VORWORT  DES  VERFASSERS. 


Im  Friihjahr  1895  schrieb  mir  Herr  Dr.  Hale,  dass  er  mein 
Lehrbuch  der  Augenheilkunde  ins  Englische  zu  ubersetzenwiinsche. 
Mit  Vergniigen  erklarte  ich  mich  einverstanden,  nicht  bloss  weil 
die  Uebersetzung  eine  Anerkennung  meiner  Arbeit  ist,  sondern  weil 
ich  auf  diese  Art  Gelegenheit  fand,  an  meinem  Buche  dies  und 
jenes  zu  andern  und  Erfahrungen  zu  verwerthen,  die  seit  der 
ersten  Niederschrift  von  mir  oder  Anderen  gemacht  worden  sind. 

Die  englische  Ausgabe  ist  also  eine  Uebersetzung  des  von  mir 
vermehrten  und  theilweise  gedtiderten  deutschen  Textes.  Hoffent- 
lich  ist  es  mir  gelungen,  die  Aenderungen  so  zu  trefifen,  dass  sie 
gleichzeitig  Verbesserungen  sind. 

A.  E.  Pick. 

Zurich,  Juni,  i8g6. 


IX 


TRANSLATOR'S  PREFACE. 


I  am  responsible  for  the  translation  of  this  work.  Except  for  the 
few  pages  relating  to  heterophoria,  I  have  tried  to  translate  the 
author's  language  so  as  to  convey  in  English  the  exact  idea 
expressed  by  the  German. 

I  hope  the  profession  will  criticize  both  the  German  and  the 
English  impartially,  so  that  we  may  add  to  the  accuracy  of  oph- 
thalmology. But  I  may  say  that  my  own  best  criticism  of  the 
book,  which,  of  all  German  literature  on  Diseases  of  the  Eye,  seems 
to  me  to  be  most  suitable  for  English-speaking  students,  is  evidenced 
by  the  fact  that  I  have  assumed  the  loving  labor  of  translating  it. 

My  thanks  are  especially  due  to  Dr.  George  Reuling,  of  Balti- 
more, for  his  many  courtesies,  to  Dr.  W.  Franklin  Coleman,  of  the 
Chicago  Post-Graduate  Medical  School,  for  his  encouragement,  and 
to  my  cousin,  Mr.  WiUiam  Buel  Hale,  for  his  kindly  aid  in  helping 
the  book  through  the  press. 

Albert  B.  Hale. 

Chicago,  August  i6,  i8q6. 
Venetian  Building. 


CONTENTS. 


PART  FIRST. 

THE  METHODS  OF  EXAMINATIONS. 

PAGE 

Introduction, 15 

A.  THE  FUNCTION  TESTS. 

I.   Acuteness  of  Vision,  Refraction,  and  Accommodation, 17 

1.  The  Principles  of  Vision, •.  17 

2.  Accommodation, 24 

3.  Shortsightedness,  Myopia,  Acuteness  of  Vision, 28 

4.  Hypermetropia, 37 

5.  Range  of  Accommodation  and  Presbyopia, 41 

6.  Astigmatism, 47 

II.   Light-Sense, 53 

III.  Color-Sense,      57 

IV.  Indirect  Vision  and  Field  of  Vision, 61 

V.   Binocular  Vision  and  Squint, ^o 

1.  Projection  of  Retinal  Images, 70 

2.  Eye  Movements, "](> 

3.  Strabismus  (Squint), 83 

B.  OBJECTIVE  METHODS  OF  INVESTIGATION. 

I.   Reflection  from  the  Cornea — Keratoscopy, 96 

II.   Focal  or  Oblique  Illumination, 9^ 

III.  The  Ophthalmoscope,      loi 

1.  Theory, loi 

2.  Description  of  the  Ophthalmoscope, 114 

3.  Use  of  the  Ophthalmoscope, '17 

(A)  Transillumination, .    .             1 18 

(B)  Examination  of  the  Fundus  of  the  Eye, 1 19 

(C)  Estimation  of  Refractive  Conditions, 1 25 

(D)  Demonstration  of  Differences  of  Level  in  the  Fundus,      .    .  135 

IV.  Measurement  of  Tension, ^37 

xi 


XU  CONTENTS. 

PART  SECOND. 

THE  DISEASES  OF  THE  EYE. 

PAGE 

Introduction, 141 

/.  Diseases  of  the  Lids 143 

1.  Diseases  of  the  Skin  of  the  Lid, 143 

2.  Diseases  of  the  Lid  Edge, .  149 

3.  Diseases  of  the  Tarsus, 154 

4.  Malpositions  of  the  Lids  and  Lid  Edges, 156 

5.  New  Growths,      165 

//.  Diseases  of  the  Lacrimal  Apparatus, 167 

1.  Diseases  of  the  Lacrimal  Glands, 169 

2.  Diseases  of  the  Lacrimal  Passage, 1 70 

///.   Diseases  of  the  Conjunctiva, l8l 

1.  Diffuse  Inflammations, 183 

2.  Inflammations  With  Formation  of  Follicles, 196 

3.  Circumscribed  Diseases, 206 

4.  Injuries  and  Their  Consequences, 214 

5.  Tumors, 218 

6.  Extremely  Rare  Diseases, 219 

Diseases  of  the  Cornea, 220 

I.  Inflammations  of  the  Cornea, 22I 

1.  General  Considerations, 221 

2.  Inflammations  With  the  Formation  of  Ulcer, 222 

3.  Inflammations  Without  the  Formation  of  Ulcer, 240 

II.   Injuries, 247 

1.  Wounds, 247 

2.  Foreign  Bodies  (Corpora  Aliena), 249 

3.  Burns, 251 

4.  Frigeration, 251 

III.  Corneal  Opacities  of  a  Non- Inflammatory  Nature, 251 

IV.  Protrusions  of  the  Cornea, 257 

Diseases  of  the  Sclera, 262 

1.  Inflammations 262 

2.  Protrusions, 263 

3.  Wounds, 265 

4.  New  Growths,      265 

Diseases  of  the  Middle  Tunic  of  the  Eye  {^Tunica  Media,  Tunica  Uvea),    ....  265 

1.  Anatomical  Introduction, 265 

2.  Physiological  Introduction, 268 

A.  Diseases  of  the  Iris, 271 

1.  Hyperemia, 271 

2.  Inflammations, 271 

3.  Injuries  and  Foreign  Bodies, .  280 

4.  New  Growths,      282 

5.  Congenital  Malformations, 283 

6.  Changes  in  Size  and  Motility  of  the  Pupil, 284 

B.  Diseases  of  the  Ciliary  Body, 286 

1.  Cyclitis, 286 

2.  Paralysis  and  Spasm  of  the  Ciliary  Muscle 288 


CONTENTS.  XI U 

PAGE 

C.   Diseases  of  the  Choroid,     .        290 

1 .  Sclerochoroiditis  Anterior, 290 

2.  Choroiditis  Exudativa, 290 

3.  Chororetinitis  Syphilitica  (Foerster) 294 

4.  Choroiditis  Suppurativa, 295 

5.  Tuberculosis  of  the  Choroid,  .    . 296 

6.  Sarcoma  of  the  Choroid, 297 

7.  Rupture  of  the  Choroid, 300 

8.  Detacliraent  of  the  Choroid, 3CK) 

9.  Congenital  Defects  in  the  Choroid  (Coloboma  Choroidese),    ....  301 
10.  Nodules  (Warts),     .        301 

Diseases  of  the  Retina  and  Optic  A^erve, 301 

Introduction, 301 

A.   Diseases  of  the  Retina, 306 

1.  Hyperemia, 306 

2.  Retinal  Hemorrhage, 307 

3.  Inflammations,      308 

4.  Occlusion  of  the  Retinal  Vessels, 311 

5.  Pigment  Degeneration  (Retinitis  Pigmentosa), 313 

6.  Detachment  of  the  Retina, 315 

7.  Glioma  Retinae, 318 

8.  Injuries,         320 

9.  Changes  Due  to  Age, ,   .    .    .  321 

10.   Medullated  (Opaque)  Nerve-Fibers,      321 

B.  Diseases  of  the  Optic  Nerve, 322 

1.  Choked  disc  (Stauungspapille),      322 

2.  Inflammation  of  the  Optic  Nerve  (Neuritis  Optica,  Papillitis),  .    .    .  324 

3.  Retrobulbar  Neuritis, 326 

4.  Atrophy, 327 

Diseases  of  the  Lens, 331 

Introduction 331 

I.  Cataract, 333 

1.  General, 333 

2.  Different  Forms  of  Cataract, 335 

3.  Causes  of  the  Formation  of  Cataract, 343 

4.  Treatment  of  Cataract, 344 

5.  Treatment — Before  and  After, 351 

6.  Cataracta  Secondaria, 354 

II.  Aphakia, 356 

III.   Changes  of  Position  of  the  Lens, 35^ 

Diseases  of  the  Vitreous, 3^0 

Introduction,      3^0 

Errors  of  Refraction,    . 3"^ 

I.  Hyperopia  (Farsightedness), 3^3 

II.  Myopia  (Shortsightedness) 3^7 

III.  Astigmatism, 37^ 

1.  Regular  Astigmatism, 37^ 

2.  Irregular  Astigmatism, 379 

3.  Anisometropia,    ' 3°' 

Amblyopia  and  Amaurosis, y>Z 

1.  Amblyopia  without  Lesion, 3°3 

2.  Intoxications, 3°9 

3.  Weaksightedness  as  a  Sign  of  Cerebral  Disease 39° 


XIV  CONTENTS. 

PAGE 

Glaucoma, 392 

1.  Introduction, 392 

2.  Varieties  of  Glaucoma 395 

(A)  Primary  Glaucoma, 395 

(B)  Secondary  Glaucoma, 400 

3.  Pathological  Anatomy ...  401 

4.  Theories, 402 

5.  Prognosis  and  Treatment, 403 

Entozoa — Parasites  in  the  Eye, 407 

I.  Cysticercus, 407 

II.   Filaria  (Thread- worms), 41 1 

Injuries  to  the  Eyeball, 411 

1.  Injuries  by  Puncture  and  Incision 412 

2.  Injuries  by  Blunt  Instruments, 413 

3.  Foreign  Bodies  Within  the  Eye, 415 

4.  Sympathetic  Inflammation  of  the  Eye, 418 

Appendix,  ....        • 423 

Disturbances  in  the  Movements  of  the  Eyes, 425 

I.   Strabismus  Paralyticus  (Paralytic  Squint), 425 

I.   Diagnostic  Signs 425 

7,.  Location  and  Causes, 434 

3.  Prognosis, 438 

4.  Treatment, 439 

II.   Strabismus  Concomitans,  Concomitant  Squint,  with  Particular  Reference  to 

Convergent  Squint 440 

1.  Vision  in  Strabismus, 440 

2.  Causes, 443 

3.  Treatment, 445 

4.  After-treatment  and  Results, 448 

III.  Latent  Strabismus,  with  Particular  Reference  to  Divergent  Squint,     ....  449 

IV.  Nystagmus, 455 

Diseases  of  the  Orbit, 457 

Introduction, 457 

1.  Injuries, 458 

2.  Inflammations, 459 

3.  Disturbances  of  the  Circulation, 461 

4.  Tumors, 466 

Appendix  A : — 

Abbreviations  used  in  Ophthalmology, 469 

Table  for  Converting  Metric  Weights  into  Troy  Weights, 470 

Appendix  B  : — 

Etymologies,      471 

Index, 477 


PART  FIRST. 

THE  METHODS  OF  EXAMINATIONS. 
INTRODUCTION. 

Observation  is  the  basis  of  all  investigation.  But  observation  in 
the  narrower  sense  need  not  be  particularly  treated  here.  To  rec- 
ognize certain  diseases,  those  of  the  conjunctiva  for  example,  by 
merely  looking  at  them,  it  is  only  necessary  to  see  them  often 
enough  in  order  to  have  their  essential  characteristics  well  im- 
pressed on  the  memory.  In  this  way  we  recognize  many  diseases 
of  the  lids,  of  the  conjunctiva,  of  the  cornea,  and  of  the  iris.  Yet 
ophthalmology  would  cut  a  poor  figure  if  observation  as  a  method 
of  examination  could  go  no  farther.  Observation  alone,  without 
accessories,  would  leave  us  in  the  lurch  when  we  come  to  the  finer 
changes  in  the  cornea,  in  the  anterior  chamber,  or  in  the  iris ;  very 
little  could  be  done  in  diseases  of  the  lens  or  of  the  vitreous  humor, 
and  nothing  at  all  in  diseases  of  the  retina,  choroid,  or  optic  nerve. 
Luckily,  however,  ophthalmology  possesses  other  excellent  means, 
not  alone  to  bring  into  view  the  finest  changes  in  those  parts  of  the 
eye  lying  superficially,  but  also  to  pierce  into  its  interior  and  to 
make  retina  and  choroid  the  object  of  closest  scrutiny. 
These  methods  are  : — 

(i)  Keratoscopy  and  Ophthalmometry^ — inspection  of  the 
images  reflected  from  the  surface  of  the  cornea ; 

(2)  Focal  illumination,  and 

(3)  The  Ophthalmoscope. 

The  first  method  gives  us  information  as  to  the  character  of  the 
surface  of  the  cornea,  its  smoothness  and  curvature.  By  means  of 
the  second  we.  see  the  finest — indeed,  by  the  aid  of  a  lens,  the  micro- 
scopically minute — changes  in  the  cornea,  in  the  anterior  chamber, 

1  Better  still,  Keratometry. 
XV 


XVI  METHODS    OF    EXAMINATIONS. 

iris,  lens,  and  in  the  anterior  part  of  the  vitreous  ;  and  by  the  thirds 
the  ophthalmoscope,  the  posterior  part  of  the  interior  of  the  eye 
lies  open  to  our  vision. 

Touch,  as  well  as  observation,  is  equally  important  to  the  oph- 
thalmologist. We  feel  of  the  eye,  either  directly,  whereby  we 
obtain  information  as  to  whether  or  not  it  is  harder  or  softer  than 
a  healthy  one ;  or  indirectly  with  an  instrument,  the  ophthalmo- 
tonometer, which,  when  applied,  proves  exactly  whether  or  not  the 
internal  tension  of  the  eye  is,  in  mercury  millimeters,  greater  or  less 
than  that  of  a  healthy  eye.  The  preceding  methods  of  investiga- 
tion are  called  objective. 

Others,  in  contrast  to  them,  are  called  subjective,  and  are  desig- 
nated as  Function  tests.  These  attempt  to  answer  the  question 
as  to  what  the  patient's  eyes  are  capable  of  doing.  The  most  im- 
portant service  is  the  recognition  of  the  form  of  external  objects — 
their  relation  in  space.  The  more  exactly  this  function  is  performed, 
the  more  acute  is  vision.  But  since  this  acuteness  of  vision  can  be 
measured  only  after  the  eye's  refractive  power  has  been  determined, 
the  principles  of  refraction  must  first  be  considered. 

Besides  relations  in  space  the  eye  possesses  two  other  functions, 
light  perception  and  color  perception.  By  light-sense  is  commonly 
understood  the  ability  to  distinguish  light  from  darkness,  or  rather, 
light  from  less  light.  By  color-sense  is  understood  the  ability  to 
respond  to  light  waves  of  different  lengths  by  individual  visual 
impressions  which  we  call  red,  yellow,  green,  blue,  etc.  Disturb- 
ances of  light  perception  are  investigated  by  means  of  Masson's 
disk,  or  the  photometer ;  disturbances  of  color  perception  by  vari- 
ous methods  that  endeavor  to  present  to  the  patient  objects  which 
can  be  distinguished  only  by  their  color,  not  by  their  form  or  bright- 
ness ;  if  the  patient  be  color-blind,  then  these  objects  obviously 
appear  alike  to  him. 

These  three  functions  of  the  eye,  acuteness  of  vision,  light-sense, 
and  color-sense,  are  to  be  tested  both  directly  (at  the  center)  and 
indirectly  (at  the  periphery).  This  examination  of  the  extent  of 
the  visual  field  or  for  any  gaps  in  it,  is  of  distinct  importance ;  the 
method  employed  is  called  Perimetry. 

Finally,  the  harmony  of  action  in  both  eyes  must  be  tested — 
monocular  and  binocular  vision  ;  and  all  defects  therein  must  be 
noted. 


TREATISE 

ON 

OPHTHALMOLOGY. 


A.  THE  FUNCTION  TESTS. 

I.     ACUTENESS    OF    VISION,    REFRACTION,    AND 
ACCOMMODATION. 

I.  THE  PRINCIPLES  OF  VISION. 

Every  point  of  light  sends  luminous  rays  into  every  direction  in 
space.  If  a  pencil  of  these  rays  falls  upon  an  even  surface  which 
is  sensitive  to  light  and  able  to  communicate  this  impression 
through  a  nerve  to  the  brain,  the  abode  of  consciousness,  then 
light  will  be  perceived,  though  by  no  means  will  every  point  of 
light  be  seen.  A  second  point,  which  also  sends  a  pencil  of  rays 
to  the  sensitive  surface,  would  increase  the  impression  of  bright- 
ness, but  would  not  be  distinguishable  from  the  first.  In  order  to 
make  this  possible,  that  is,  to  establish  vision,  two  conditions  must 
be  fulfilled  :— 

(i)  In  front  of  the  sensitive  surface  there  must  be  a  dioptric 
apparatus  which  collects  the  divergent  rays  and  unites  them  as  an 
image  on  this  perceptive  surface,  and — 

(2)  The  perceptive  surface  must  be  a  mosaic,  the  individual  parts 
of  which  can  be  stimulated  by  luminous  rays,  and  this  stimulation 
must  be  carried  to  the  brain  without  affecting  the  other  parts  of 
this  surface.^ 

These  two  essential  conditions  are,  as  a  matter  of  fact,  fulfilled  in 
the  eye  of  man  (and  of  vertebrates  in  general).  The  cornea,  the 
aqueous,  lens,  and  the  vitreous  form  together  a  dioptric  system 
which  has  under  certain  conditions  the  property  of  uniting  a  homo- 
centric  entering  pencil  of  rays  into  an  image  on  the  retina,  the  light- 

^  This  does  not  imply  that  any  point  of  the  retina  is  completely  independent  of  other 

points.     Compare //.  j6,  J-.?. 

17 


1 8  THE    FUNCTION    TESTS. 

perceptive  tissue  of  the  eye.  Each  luminous  object  can  be  consid- 
ered as  consisting  of  an  infinite  number  of  luminous  points ;  each 
of  these  luminous  points  reproduces  its  own  image  on  the  retina, 
and  from  these  infinite  images  a  picture  on  the  retina  is  constructed 
geometrically  identical  with  the  luminous  object.  This  fact  can  be 
demonstrated  in  the  following  manner :  Get  the  fresh  eye  of  a  white 
rabbit;  after  carefully  clearing  from  the  bulb  all  shreds  of  muscle 
and  other  tissue,  hold  the  eye  with  the  cornea  toward  a  bright, 
easily  recognized  object,  say  the  window  or,  even  better,  a  good- 
sized  gas  flame  in  a  dark  room.  Now,  by  looking  at  the  back  of 
the  eye,  one  can  see,  because  it  has  no  pigment  and  is  compara- 
tively transparent,  the  inverted  and  much  reduced  retinal  image  of 
the  gas  flame. 

If  the  form  of  the  gas  flame  is  not  recognizable  on  account  of  the  great  reduction  in 
the  size  of  the  image,  then  take  two  gas  flames  at  a  distance  of  one  meter  from  each 
other,  and  hold  before  the  one  a  red,  before  the  other  a  green  glass  ;  then  there  is  seen 
on  the  back  of  this  rabbit's  eye  a  red  and  a  green  point,  the  red  standing  at  the  right 
when  its  gas  flame  was  at  the  left,  and  vice  versa.  This  is  obviously  a  proof  that  these 
little  points  must  be  the  inverted  images  of  the  gas  flame. 

The  second  condition,  the  mosaic  construction  of  the  sensitive 
retina,  is  also  fulfilled  in  the  human  and  the  vertebrate  eye,  but 
without  a  microscope  this  fact  cannot  be  so  easily  proved  as  the 
first.  In  the  chapter  on  "  Diseases  of  the  Retina  "  a  picture  of  the 
human  retina  is  given,  magnified  about  350  times.  This  picture,  in 
at  least  the  two  outermost  retinal  layers,  shows  the  mosaic  struc- 
ture ;  the  innermost  of  these,  the  rods  and  cones,  are  to  be  con- 
sidered, of  course,  as  the  sensitive  nerve  elements.  A  dioptric 
system  giving  images  geometrically  similar  to  the  external  objects, 
but  inverted  and  smaller,  must  have  the  following  properties : — 

(i)  Each  refracting  medium  must  be  transparent  and  homo- 
geneous, i.  e.,  of  equal  refractive  index  in  all  parts. 

(2)  The  refractive  surfaces  of  all  the  media  must  be  spherical. 

(3)  The  focal  points  of  all  refractive  surfaces  must  lie  on  the 
same  plane ;  in  other  words,  the  systems  must  be  concentric. 

Even  if  these  three  conditions  are  fulfilled,  exact  images  will 
result  only  from  such  objects  as  send  rays  nearly  perpendicular  to 
the  surface  of  the  cornea.  Physics  gives  us  this  law :  "  A  homo- 
centric  pencil  of  rays  in  passing  through  a  centered  system  of 
spherical  refracting  surfaces  will  form  an  exact  image  only  when 
the  angle  of  entrance  is  small."     By  the  angle  of  entrance  is  meant 


THE    PRINCIPLES   OF    VISION.  I9 

that  angle  which  the  entering  ray  makes  with  the  perpendicular  to 
the  refractive  surface. 

Since,  on  the  one  hand,  the  human  cornea  is  strongly  curved, 
and,  on  the  other  hand,  is  an  appreciable  segment  of  a  sphere,  a  point 
of  light  at  infinity,  even  if  on  the  axis,  sends  a  pencil  to  the  cornea 
whose  peripheral  rays  form  a  large  angle  of  entrance,  and  conse- 
quently cannot  produce  an  image  at  the  same  point  as  do  the 
central  rays.  Therefore,  even  the  most  favorably  situated  point 
cannot  be  reproduced  in  an  exact  image.  But  the  iris  stretched 
behind  the  cornea  prevents  the  entrance  of  the  peripheral  rays  of 
any  pencil,  and  these  do  not,  therefore,  reach  the  interior  of  the 
eye  at  all. 

Any  point  of  light  not  on  or  near  the  axis  of  a  dioptric  system 
sends  even  those  rays  lying  nearly  in  front  of  the  pupil  at  a  rather 
obtuse  angle,  and  they  cannot,  therefore,  in  any  way  form  an  exact 
image.  As  we  shall  see  below,  however,  these  oblique  rays  are 
formed  into  an  image  owing  to  the  special  construction  of  the 
crystalline  lens. 

The  three  properties  just  mentioned  are  only  approximately  correct  in  the  human  eye. 

Under  (i).  That  the  transparency  is  not  perfect  can  be  demonstrated  on  the  cornea  in 
the  following  manner :  In  the  dark  room  place  a  lamp  opposite  a  man,  and  with  a  con- 
vex lens  unite  a  pencil  of  rays  at  their  focal  point  on  the  cornea;  this  spot  will  then  seem 
gray  because  there  is  enough  light  reflected  from  the  corneal  cells  to  be  perceived  by  the 
observer  (see  /.  gS,  gg). 

The  incomplete  transparency  of  the  lens  can  be  still  easier  perceived  in  the  same  way, 
or  can  be  demonstrated  on  the  cadaver  without  any  apparatus :  Open  the  eye  of  a  man 
over  forty  and  place  it  in  water;  then  the  middle  part,  the  so-called  nucleus,  appears 
more  or  less  yellow,  according  to  the  age  of  the  individual.  This  fact  proves  that  the 
transparency  of  the  lens  is  by  no  means  perfect. 

The  vitreous  is  much  clearer,  although  there  are  always  small  areas  through  which  the 
light  does  not  pass.  One  can  best  demonstrate  this  on  one's  own  eye  entopically  ;  some 
persons,  when  using  the  microscope,  notice  these  physiological  defects  of  the  vitreous  as 
little  strings  of  beads  or  individual  circles  with  a  bright  center  ;  in  my  own  eye  I  can  see 
them  best  in  damp  weather  ;  with  the  eyelids  closed  they  can  sometimes  be  seen  by  turn- 
ing the  face  toward  a  bright  surface.  Of  course,  a  clear,  smooth  field  of  vision  is  the 
best  background  for  perceiving  these  little  opacities,  which  move  about  in  the  vitreous 
and  are  consequently  called  mouches  volantes. 

Under  (2).  The  spherical  curve  of  the  refractive  surfaces  is  not  mathematically  exact 
in  the  eye ;  the  surface  of  the  cornea,  which  is  the  most  important,  is,  in  fact,  so  little 
the  arc  of  a  circle  that  the  difference  can  be  perceived  without  much  trouble. 

As  is  well  known,  a  reflection  of  some  light  will  always  be  caused  when  a  pencil  of 
rays  passes  from  one  transparent  medium  to  another.  If  the  refractive  surfaces  of  both 
media  are  spherical,  and  the  convex  side  is  turned  toward  the  weaker  refracting  medium 
(the  air),  then  upright  images  of  distant  objects  will  be  formed  which  are  the  smaller  the 
shorter  the  radius  of  curvature  of  this  surface  is ;   consequently,  the  size  of  the  images 


20  THE   FUNCTION    TESTS. 

gives  us  a  key  to  the  radiifs  of  curvature  of  the  reflecting  surfaces.  A  corneal  image  can 
be  obtained  as  follows  :  Cut  from  stiff  paper  a  piece  about  20  cm.  square  ;  make  a  hole 
in  the  middle  6  to  8  mm.  diameter,  and  place  a  man  with  his  back  to  the  window  and 
hold  the  paper  about  30  cm.  in  front  of  one  of  his  eyes.  If  the  observer  looks  through 
the  hole  at  the  cornea  of  this  man,  and  if  he  at  the  same  time  looks  at  the  hole,  then  at 
exactly  the  middle  of  his  cornea  will  be  seen  a  very  much  reduced  image  of  the  piece  of 
white  paper.  Then  ask  him  to  look  at  the  upper  or  lower  edge  of  the  paper,  when  the 
image  of  the  paper  will  be  reflected,  not  from  the  center  of  the  cornea,  but  from  the 
edges,  and  appears  very  much  different,  that  is,  larger  and  longer,  a  proof  that  the  edges 
of  the  cornea  are  flatter  than  the  middle. 

Exact  measurements  have  shown  that  the  cornese  differ  in  different  men.  Some  have 
the  curvature  of  one  ellipsoid,  others  of  another,  but  they  all  differ  from  the  mathematical 
figure  by  obvious  irregularities,  to  be  discussed  later. 

The  anterior  and  posterior  surfaces  of  the  lens  are  also  curves  lacking  mathematical 
accuracy,  but  as  the  measurement  of  the  images  reflected  from  them  is  much  more  dift'er- 
ent  than  in  the  case  of  the  cornea,  these  irregularities  are  not  so  well  known.  In  practice, 
however,  the  small  parts  of  the  anterior  and  posterior  surfaces  of  the  lens  used  in  ordi- 
nary vision  can  be  regarded  as  spherical. 

Under  (3).  Considering  a  corneal  surface  and  the  anterior  and  posterior  lens  surfaces 
spherical,  the  three  nodal  points  ought  to  be  in  one  plane,  but,  according  to  Helmholtz's 
measurements,  lately  confirmed  by  Tscherning,  this  is  not  the  case.  The  human  eye  is 
"decentered,"  although  in  so  slight  a  degree  as  to  be  practically  of  no  value. 

Let  us  now  follow  the  course  of  a  pencil  of  light  through  the 
dioptric  system  of  the  eye  in  order  to  obtain,  theoretically,  an  idea 
of  what  has  resulted  from  this  experiment  on  the  white  rabbit's 
eye.  Take  the  simplest  case  of  an  eye  without  any  lens.  In  such 
an  eye  there  is  only  one  refracting  surface,  the  cornea,  and  two 
refractive  media,  air  and  water.  The  refractive  index  of  the  cor- 
nea, of  the  aqueous,  and  of  the  vitreous  can  all  be  considered  as 
that  of  water.^ 

In  such  an  eye  looking  toward  a  point  of  light  on  its  axis  at 
infinity,  the  rays  falling  on  the  cornea  will  be  united  in  an  image 
lying  about  3 1  nun.  behind  the  apex  of  the  cornea,  that  is,  behind  the 
retina.  This  point  is  called  the  posterior  focal  point  of  the  system 
{p,fy  of  Fig.  i).  If  the  object  is  brought  closer  to  the  eye  on  its 
axis,  the  convergence  of  the  rays  in  the  anterior  of  the  eye  becomes 
less,  or,  in  other  words,  the  image  passes  at  first  gradually  and 
then  more  rapidly  toward  the  right,  supposing  the  object  to  be 

^  According  to  Krause,  the  refractive  index  of 
water         =     1-3342 
cornea       ^=     1.3507 
aqueous     =     1.3420 
•  vitreous     ^     I  3485 ;  taking  that  of 

air  =     l.o 


THE    PRINCIPLES    OF    VISION.  21 

moved  at  the  same  rate  of  speed ;  finally,  this  point  of  light  will 
come  so  close  to  the  eye  that  the  refraction  of  the  rays  on  entering 
the  cornea  is  just  enough  to  make  divergent  rays  parallel  (the  red 
lines  of  Fig.  /,  A).  In  other  words,  the  image  now  lies  toward  the 
right  at  infinity.  The  point  on  the  axis  from  which  divergent  rays 
proceed  parallel  within  the  eye  is  called  the  anterior  focal  point  of 
the  eye  {a,  f,  of  Fig.  /). 

If  the  position  of  the  anterior  and  posterior  focal  points  is  known, 
it  is  easy  to  draw  the  image  of  any  object  whatever.  Let  p  {Fig. 
I,  E)  be  a  given  object ;  take  two  rays  diverging  from  it  and  find 
their  meeting-point.  Since  all  other  rays  of  a  homocentric  pencil 
must  pass  through  this  meeting-point  (assuming  that  the  point  p 
is  not  too  far  from  the  axis),  then  the  desired  image  lies  obviously 


Fig.  1. — Passage  op  Luminous  Ravs  through  an  Aphakic  Eye. 

at  this  meeting-point.  Let  us  take  for  example  those  rays  whose 
course  we  already  know  : — 

(i)  The  ray  parallel  to  the  axis,  which  must  strike  the  posterior 
focal  point  of  the  second  medium,  and 

(2)  The  ray  passing  through  the  anterior  focal  point,  which 
must  run  parallel  to  the  axis  in  the  second  medium.  At  the  meet- 
ing-point of  these  two  rays  lies  /',  the  image  of  p. 

In  a  normal  eye  with  a  lens  the  conditions  are  by  no  means  so 
simple,  for  it  is  easy  to  see  that  the  form  of  the  lens  and  the  fact 
that  its  refractive  index^  is  greater  than  that  of  water  increase  the  con- 
verging power  of  the  whole  system.  Consequently,  both  the  anterior 
and  posterior  focal  points  are  closer  to  the  apex  of  the  cornea. 

1  The  refractive  index  of  the  lens,  assuming  it  to  be  homogeneous  =  l.4545>  '^^ 
I-454I- 


22  THE    FUNCTION    TESTS. 

A  physiologically  normal  eye  is  one  having  the  anterior  focal 
point  13  mm.  in  front  of,  and  its  posterior  22  mm.  behind,  the  apex 
of  the  cornea.  Since  22  mm.  is  also  the  distance  of  the  fovea  cen- 
tralis retinai  from  the  apex  of  the  cornea,  a  normal  eye  is  one  zvhose 
posterior  focal  point  lies  on  the  retina.  This  is  called  an  emmetropic 
eye,  to  distinguish  it  from  the  ametropic  eye,  in  which  the  poste- 
rior focal  point  lies  either  before  or  behind  the  retina. 

The  question  now  is,  whether  it  is  possible,  by  means  of  the 
anterior  and  posterior  points  alone,  to  find  in  this  compound  sys- 
tem the  image  formed  by  the  rays  from  a  certain  object.  Let  us 
take  in  this  case,  also,  two  construction  rays  from  the  pencil,  one 
passing  through  the  anterior  focal  point  and  consequently  running 
in  the  vitreous  parallel  to  the  axis,  the  other  striking  the  cornea 
parallel  to  the  axis  and  consequently  reaching  the  posterior  focal 
point  in  the  vitreous.     We  see  at  once,  however,  that  these  two 


jfjf' 

Fig.  2. — Construction  of  thb  Image  by  Means  of  the  Foci  and  Principal  Planes. 

diverging  rays  are,  in  this  case,  far  from  sufficient.  To  determine 
any  line  two  points  are  necessary ;  but  here  we  have  only  one 
point  for  each  ray  of  exit.  The  case  of  the  eye  without  a  lens  is 
somewhat  different  {Fig.  i),  for  there  the  point  on  the  surface  of 
the  cornea  on  which  the  entering  ray  fell  was  also  a  point  of  the 
ray  of  exit,  but  in  a  compound  dioptric  system  that  is  not  to  be 
taken  for  granted,  and  by  mathematical  analysis  it  is  found  not  to 
be  the  case.  It  is  also  clear  that  the  two  cardinal  points,  the  ante- 
rior and  posterior  foci  of  a  compound  system,  are  not  enough  to 
give  us  the  image  of  an  object.  We  need  a  second  pair  of  cardinal 
points,  the  two  points,  /i',h"  {Fig.  2),  and  the  two  principal  planes, 
H' ,  H" ,  which,  in  the  physiological  eye,  lie  2  or  2.5  mm.  behind 
the  apex  of  the  cornea.^ 

*  Tb«  first  principal  point  lies  1. 94  nim.,  the  second  2.36  mm.,  behind  the  corneal 
apex,  a  distance  apart  of  scarce  0.5  mm. 


THE    PRINCIPLES    OF    VISION.  23 

By  means  of  this  we  can  now  find  the  image,  p' ,  of  the  object,  /, 
as  follows :  Prolong  the  entering  ray,  pf ,  to  where  it  strikes  the 
first  principal  plane ;  continue  it  parallel  to  the  axis  as  far  as  the 
second  principal  plane,  where  it  becomes  in  its  new  position  a  ray 
of  exit.  The  second  point  in  this  ray  of  exit  is  determined  by  the 
fact  that  the  ray  must  run  in  the  vitreous  parallel  to  the  axis. 
Now,  prolong  a  ray  coming  from  /  parallel  to  the  axis  in  the  first 
meridian  as  far  as  the  first  principal  plane,  advance  its  point  of  con- 
tact, still  parallel  to  the  axis,  into  the  second  principal  plane,  thus 
giving  us  again  a  point  on  the  ray  of  exit,  and  prolong  it  through 
the  posterior  focal  point.  The  image,  p' ,  lies  at  the  intersection  of 
these  two  rays. 

With  the  unusually  short  distance  of  the  two  principal  planes 
from  each  other,  it  is  permissible  to  neglect  it  altogether  and  to 
consider  them  as  one.  The  construction  of  the  image  is  thereby 
essentially  simplified,  and  differs  from  that  of  an  aphakic  eye 
{Fig.  i)  only  by  the  fact  that  the  principal  plane  in  the  former  case 
plays  the  part  of  the  corneal  surface  in  the  latter;  that  is  to  say,  it 
gives  us  the  principal  point  of  the  entering  ray,  which  we  can  con- 
sider as  belonging  also  to  the  ray  of  exit. 

In  practice,  especially  in  using  the  ophthalmoscope  or  in  study- 
ing the  laws  of  refraction  and  projection,  we  have  still  a  third  pair 
of  cardinal  points,  the  anterior  and  posterior  nodal  points  {k'  and  k" 
o{  Fig.  2).  These  points  lie  6.95  mvi.  and  7.37  nivi.  behind  the  cor- 
neal apex,  separated,  in  this  case,  less  than  0.5  vim.  Their  signifi- 
cance is  due  to  the  fact  that  rays  in  the  air,  which  would  strike  the 
first  nodal  point  in  the  vitreous,  are  continued  in  this  medium 
parallel  to  their  original  direction,  as  if  they  came  from  the  second 
nodal  point;  consequently,  by  ignoring  the  slight  interval  between 
them,  we  have  the  following  deduction :  rays  of  entrance  striking 
the  nodal  point  are  co7itinued  practically  tmrefracted  through  the  whole 
system.  Considering  this  fact,  the  nodal  point  has  been  named 
the  "  point  of  intersection  of  the  rays  of  direction."  This  point 
becomes  in  the  normal  eye  practically  the  posterior  pole  of  the 
lens.  Knowing  this  point  of  intersection,  we  can  determine  the 
image  when  we  have  the  distance  of  the  object  from  the  corneal 
apex.  In  the  emmetropic  eye,  when  the  object  lies  at  infinity,  or 
with  such  a  short  focal  distance,^  practical  infinity,  as  we  may  call 

1  The  anterior  and  posterior  focal  distances  are  respectively  the  distances  of  the  ante- 
rior focus  from  the  anterior  principal  plane,  and  that  of  the  posterior  from  the  posterior 
principal  plane. 


24  THE    FUNCTION   TESTS. 

anything  at  5  nun.  or  beyond,  the  im^ge  is  formed  with  nearly 
absolute  accuracy  on  the  retina.  To  determine  the  location  of  this 
image,  prolong  rays  from  the  object  to  the  nodal  point  and  extend 
them  to  the  retina ;  where  these  rays  strike  the  retina  we  find  the 
image,  because  all  rays  falling  on  the  cornea  must  here  intersect 
the  rays  of  direction.  If,  according  to  this,  a  diagram  is  made  of  a 
distant  line  on  a  piece  of  paper,  we  find  that  the  image  of  the  line 
is  smaller  and  inverted.  What  was  true  of  the  rays  in  one  plane 
(say  in  the  drawing,  Fig.  2)  is  necessarily  true  of  all  rays  outside 
the  drawing  which  strike  the  cornea.  Simple  reflection  will  show, 
therefore,  that  all  objects  in  space  must  be  reproduced  on  the  retina 
of  an  emmetropic  eye  as  inverted,  reduced,  and  geometrically  exact 
images. 

Imagine  an  emmetropic  eye  looking  toward  a  house  at  a  great  distance ;  prolong  lines 
from  the  comers  of  this  house  to  the  point  of  intersection  of  the  rays  of  direction  and 
continue  them  to  the  retina.  Any  two  such  rays  of  direction  will  give  us  a  plane  ;  in 
any  such  plane  we  have  these  two  retinal  points  and  the  nodal  p)oint  forming  a  triangle 
similar  to  that  formed  by  the  nodal  point  and  the  two  original  points  on  the  object.  As 
all  lines  are  necessarily  proportionate  in  the  two  triangles,  we  must  conclude  that  the 
house  in  the  image  is  geometrically  symmetrical  to  the  house  taken  as  object. 


2.  ACCOMMODATION. 

In  the  previous  section  we  have  discussed  the  first  condition  of 
vision,  that  is,  the  impression  on  an  emmetropic  eye  of  an  optical 
image  similar  to  the  object.  Now  we  know  from  daily  experience 
that  the  normal  eye  can  see  with  equal  distinctness  near  as  well  as 
far  objects ;  this  is  possible  in  the  emmetropic  eye  only  when  a 
change  takes  place  for  near  vision.  Before  we  investigate  what  this 
change  consists  of  and  how  it  is  accomplished,  we  must  show,  ot 
course,  that  this  change  is  indispensable,  for  it  is  not  possible  to 
see  a  near  and  far  object  with  equal  distinctness  at  the  same  time, 
as  either  the  near  object  is  clear  or  the  far  one  hazy,  or  vice  versa. 

Physiology  illustrates  this  by  means  of  "  Scheiner's  experi- 
ment." ^  The  following  experiment  is  less  troublesome  :  Take  two 
cards,  one  with  large,  the  other  with  small  print ;  cut  out  of  the 
latter  a  number  of  words  and  so  place  it  that  words  of  the  coarser 
print  on  the  other  card  at  a  greater  distance  will  show  through 

^  Described  in  most  text-books  of  physiology.  Sometimes  of  importance  in  demon- 
strating a  cataract  operation. 


ACCOMMODATION,  25 

these  holes  ;  the  observer,  sitting  at  a  proper  distance  before  the 
cards  and  trying  to  read,  will  at  once  notice  that  when  reading  the 
near  type  the  farther  will  look  as  if  covered  with  tissue  paper  and 
is  unreadable,  while  if  the  eye  looks  through  a  hole  at  a  word  on 
the  far  card,  the  near  type  is  indistinct. 

This  change  in  the  eye,  called  Accommodation,  can  be  brought 
about  in  two  ways,  either  by  displacement  of  the  retina  backward 
(in  Figs.  I  and  2  toward  the  right),  or  by  a  change  in  the  dioptric 
apparatus,  this  last  necessarily  implying  a  change  of  refractive 
strength,  or,  in  other  words,  a  shortening  of  the  focal  distance. 

That  accommodation  for  near  objects  by  displacement  of  the 
retina  backward  (lengthening  of  the  bulb)  can  take  place  has  been 
asserted  by  various  ophthalmologists  recently,  Schrieller  among  the 
number.  Considering  the  softness  of  most  eyes  and  the  circum- 
stance that  a  displacement  of  the  retina  of  only  0.6  mm.  backward 
would  suffice  to  accommodate  an  emmetropic  eye  from  infinity  to 
0.5  ;;/.,  this  idea  is  not  altogether  improbable.  Nevertheless,  even 
the  advocate  of  this  idea  confesses  that  a  backward  displacement  of 
the  retina  can  take  place  only  with  the  severest  strain  on  accommo- 
dation and  convergence,  which  is  not  a  normal  process.  It  can  be 
said,  therefore,  with  all  certainty,  that  this  extension  of  the  axis 
during  ordinary  accommodation  plays  no  part. 

If  accommodation  for  a  near  object  is  brought  about  in  the  diop- 
tric apparatus,  the  following  possibilities  must  be  considered : — 

(i)  Increase  of  the  refractive  index. 

(2)  Advance  of  the  lens,  that  is,  its  approach  toward  the  cornea. 

(3)  Increased  curvature  of  the  refracting  surfaces. 

The  first  possibility  need  not  be  examined,  since  the  short  time 
necessary  for  accommodation  gives  no  chance  for  a  change  in  the 
density  of  the  refractive  media.  The  second  possibility,  accommo- 
dation through  advance  of  the  lens  toward  the  cornea,  cannot  be 
so  lightly  dismissed,  and  has  had,  as  a  matter  of  fact,  numerous 
advocates  of  the  highest  scientific  rank.  But  exact  experiments 
show  that  although  the  anterior  lens  surface  does  approach  the 
cornea  during  accommodation,  this  slight  change  of  position  is 
never  enough  to  account  for  the  reduced  focal  distance  that  takes 
place.  A  positive  visible  displacement  of  the  lens  will  be  neces- 
sary, and  as  this  does  not  happen  we  can  dismiss  the  idea. 

The  third  possibility  remains,  accommodation  by  means  of  in- 
creased curvature  of  the  refractive  surfaces  of  the  cornea  and  lens. 


26  THE    FUNCTION    TESTS. 

Various  experiments  have  conclusively  proven  that  the  cornea  is 
not  altered  during  accommodation.  If  this  were  so,  measurements 
of  the  corneal  images  would  show  that  they  become  smaller  by 
increased  corneal  curvature  for  accommodation.  They  do  not, 
however.  Moreover,  the  cornea  can  be  practically  removed  from 
the  dioptric  apparatus  by  covering  it  with  water,  and  yet  accom- 
modation is  not  at  all  affected.  If  experiments  on  the  cornea  give 
negative  results,  exactly  the  reverse  is  true  of  those  on  the  lens. 
Here  we  find  during  accommodation  an  actual  reduction  in  the 
size  of  the  image  reflected  from  the  anterior  lens  surface,  a  suffi- 
cient proof  that  this  surface  has  meanwhile  been  increased  in 
curvature. 

The  images  reflected  from  the  cornea  and  from  the  anterior  and 

posterior  lens  surfaces  are  called  Purkinje-Sanson's  figures.     Fig.^ 

shows  them  as  they  would  appear  to  the  reader  looking  into  the 

eye  from  in  front  and  to  the  left  of  the  patient, 

Oand  seeing  the  reflection  of  a  candle  in  front  and 
to  the  right  of  him.  The  image  marked  8  is  up- 
right, since  it  comes  from  the  cornea  (with  a  radius 
of  8  mm.).  It  is  bright  because  its  refractive  in- 
dex differs  greatly  from  that  of  air.^ 
8     /o    6  The  image  marked  lo  is  also  upright,  is  larger 

Fig.  3.— porkinjb-San-     than  the  first  and  much  dimmer,  so  dim,  in  fact, 

SON  s   Figures.      (Ac- 

cording  to  HeimhoUz.)  that  its  demonstration  is  often  difficult  for  the 
beginner.  It  comes  from  the  anterior  lens  sur- 
face, that  has  a  radius  of  lo  mm.  Its  dimness  is  due  to  the  fact 
that  the  difference  between  the  index  of  refraction  of  the  lens  and 
that  of  the  aqueous  is  very  small.  Finally,  the  image  marked  6  is 
inverted,  is  the  smallest,  and  is  somewhat  lighter  than  that  marked 
10.  Its  inversion  is  due  to  the  fact  that  it  is  reflected  from  the 
posterior  lens  surface  acting  as  a  concave  mirror;^  the  small  size 
is  explained  by  the  strong  curvature  of  this  concave  mirror,  whose 
diameter  is  only  6  mm. 

It  is  not  so  easy  to  demonstrate  these  images  on  the  lens,  but  I  shall  later  (see  /.  loo) 
give  a  method  by  means  of  which  these  Purkinje-Sanson  images  can  he  made  evident  to 
the  most  inexperienced. 

1  A  greater  difference  between  the  refractive  indices  of  the  media  implies  brighter 
reflection  from  the  surfaces. 

2  With  reference  to  the  path  of  the  luminous  rays. 


ACCOMMODATION.  2/ 

The  attempt  to  measure  the  lens  is  still  more  difficult.  Helm- 
holtz,  with  the  aid  of  his  ophthalmometer,  first  did  this  success- 
fully. His  measurements  conclusively  prove  Kramer's  demonstra- 
tions that  during  accommodation  the  greater  curvature  takes 
place  at  the  anterior  lens  surface  (see  Fig.  4).  This  reduction  in 
curvature  can  amount  to  about  4  ;//;;/.  The  posterior  lens  sur- 
face is  likewise  increased  in  curvature  during  accommodation,  but 
only  to  the  extent  of  0.5  ///;//.,  so  small  a  change  and  such  an  uncer- 
tain measurement  that  no  attention  need  be  paid  to  it. 

Finally,  we  must  investigate  in  what  manner  this  increased  curva- 
ture takes  place.  We  know  that  the  accommodation  is  subject  to 
the  will,  and  that  all  involuntary  motions  of  the  body  are  the  result 
of  muscular  action  ;  consequently,  a  muscle  connected  by  a  nerve 
with  the  brain  must  be  the  mechanism  that  produces  this  change 


fornea  prvpef 
J)e.scemef 'Jfemimne 
-Ji'utalheUufTi 
-  Spi'ncf^rjrutts 

XJ^c&stiu  OUtant 

Fig.  4. 
The  left  half  represents  the  eye  at  rest,  the  right  during  accommodation. 

in  form.  We  have  such  a  muscle  in  the  interior  of  the  eye,  close 
to  the  lens,  though  it  is  unstriated  instead  of  striated.  Probably  a 
good  explanation  of  the  fact  that  a  muscle  is  the  cause  of  this  action 
was  given  by  Bruecke  and  Bowman  within  a  comparatively  recent 
period.  This  musculus  ciliaris  {Fig.  4)  surrounds  the  equator 
of  the  lens  like  a  ring;  if  the  muscle  contracts,  thereby  making 
the  ring  smaller,  one  can  imagine  the  ring  pressing  on  the  equator, 
and  the  lens  must  then  yield  at  the  anterior  pole,  that  is,  toward 
the  pupil.  This  view  finds  an  earnest  advocate  in  Heinrich  Muel- 
ler. Proof  was,  however,  not  conclusive,  for  Helmholtz  showed 
that  the  action  of  the  ciliary  muscle  was  not  direct  upon  the  lens, 
but  indirect  through  the  Zone  of  Zinn  (see  Fig.  /).  Numer- 
ous measurements  have  shown  that  a  lens  is  thicker  antero-poste- 
riorly  after  extraction  from  the  eye  than  it  was  before ;  the  lens, 
therefore,  is  not  in  a  condition  of  physical  equilibrium  so  long  as 


28  THE    FUNCTION   TESTS. 

it  is  in  the  eye,  being  flattened  on  account  of  the  tension  that  the 
fibers  of  the  Zone  of  Zinn  exert  on  the  lens  capsule. 

But  the  Zone  of  Zinn  is  attached  to  the  ciliary  processes,  and  a 
contraction  of  the  ciliary  muscle  must,  therefore,  narrow  the  diam- 
eter of  the  attachment  of  the  Zone  of  Zinn.  The  zone  being  thus 
relaxed,  the  lens  is  allowed  to  grow  rounder  by  its  own  elasticity. 

This  description  may  be,  perhaps,  too  schematic  in  explaining  the 
action  of  such  a  complicated  muscle. 

Schoen,  assuming  that  each  one  of  the  three  sets  of  muscular  fibers  plays  according 
to  its  course  its  individual  part  in  accommodation,  has  developed  a  specific  theory  to 
explain  accommodation,  but  it  has  not  yet  been  accepted  by  many  ophthalmologists. 

In  op|X)sition  to  the  Helmholtz  theory  of  accommodation  stands  that  of  Tscherning. 
Helmholtz  ascribes  accommodation  for  near  objects  to  relaxation  of  the  Zone  of  Zinn, 
while  Tscherning  declares  the  opposite  to  be  true,  namely,  that  tension  on  the  Zone  of 
Zinn  allows  the  anterior  surface  of  the  lens  to  be  more  strongly  curved,  at  least  in  the 
neighborhood  of  the  anterior  pole.  The  edges  of  the  lens  are  likewise,  so  says  Tscher- 
ning, flattened  by  tension  on  the  zone;  but  these  edges  lie  behind  the  iris  and  are,  there- 
fore, of  no  use  in  vision.  How  a  contraction  of  the  ring-like  ciliary  muscle  can  put  the 
zonula  on  the  stretch  I  cannot  explain  to  the  reader,  for  I  do  not  understand  it  myself. 


3.  SHORTSIGHTEDNESS.  MYOPIA,  M.     ACUTENESS  OF 

VISION,  V. 

In  the  preceding  section  it  was  explained  that  the  emmetropic 
eye  has  the  power  of  independently  accommodating  for  a  near 
object.  But  there  are  plenty  of  eyes  that  even  at  rest  are  adjusted 
for  only  certain  distances  this  side  of  infinity ;  such  eyes  are  short- 
sighted, and  the  condition  is  known  as  Myopia. 

The  word  myopia  means  that  shortsighted  people  generally  half  close  the  eyes  when 
looking  at  a  distant  object.  The  word  "  shortsightedness  "  ought,  therefore,  to  be  pre- 
ferred, because  it  describes  tlie  condition  itself  and  not  a  mere  physical  property. 

If  a  shortsighted  eye  at  rest  looks  at  r  cm.  distance,  and  receives 
an  image  of  it  on  the  retina,  then  the  image  of  every  point  beyond 
must  lie  in  front  of  the  retina;  a  point  at  infinity,  therefore,  has  its 
image  in  front  of  the  retina.  If  a  point  lies  at  00  infinity  and  on 
the  axis  of  a  lens,  its  image  lies  at  the  focal  distance  of  the  lens ; 
consequently  we  can  call  shortsightedness  that  refractive  condition 
of  an  eye  at  rest  in  which  the  focal  distance  is  in  front  of  the  retina 

{Fig-  5.  0- 

What  can  explain  the  fact  that  the  focus  does  not  lie  upon  the 
retina?     There  are  several  possible  explanations. 


MYOPIA    AND    ACUTENESS    OF   VISION. 


29 


We  first  think  of  the  dioptric  apparatus,  as  several  deviations 
from  a  normal  condition  can  cause  a  shortening  of  the  focal  dis- 
tance : — 

(i)  A  too  high  refractive  index.  Shortsightedness  of  this  kind 
does  actually  exist,  and  at  least  that  myopia  which  here  and  there 
precedes  a  cataract  is  explained  by  many  ophthalmologists  as  a 
thickening  of  the  lens  and  nucleus  and  a  consequent  increase  in 
refractive  power. 

(2)  An  unusual  position  of  the  lens,  such  as  a  forward  luxation, 
can  cause  shortsightedness.  As  an  example,  we  often  see  myopia 
just  before  the  development  of  senile  cataract,  which  is  explained 
by  many  observers  as  an  increase  in  the  size  of  the  lens  and  a 
consequent  advance  toward  the  iris.  In  glaucoma,  also,  and  in  a 
certain  form  of  choroiditis,  some  American  ophthalmologists  report 


^yopLC  c. 

Fig.  5. — Position  op  the  Retina. 
(a)  In  front  of,  (b)  at,  and  (c)  behind  the  focus. 


that  an  increased  collection  of  fluid  behind  the  lens  presses  it  for- 
ward, and  that  the  shortsightedness  disappears  as  soon  as  the 
exciting  disease  is  cured. 

(3)  Finally,  the  dioptric  apparatus  can  be  abnormal  if  the  refract- 
ing surfaces  are  of  too  strong  a  curvature.  A  case  is  mentioned 
by  v.  Reuss  of  a  myope  whose  corneal  radius  was  only  6.5  vim. 
(compared  with  'j.'j  to  8.0  mm.  of  the  normal  eye).  Even  if  all  the 
shortsightedness  could  not  be  explained  thereby,  there  is  no  doubt 
that  part  of  it  was  due  to  this  cause. 

The  variations  in  corneal  measurements  within  physiological  bounds  have  naturally- 
some  influence  on  the  position  of  the  image  ;  anything  less  than  7.7  mm.  would,  of 
course,  increase  a  shortsightedness  due  to  other  causes,  but  numerous  measurements  have 
proven  that  in  shortsightedness  the  corneal  radius  is,  indeed,  rather  smaller  than  it  is 
under  other  conditions. 

(4)  The  anterior   lens   surface  with  a  strong   curvature  much 


30  THE    FUNCTION    TESTS. 

oftener  causes  shortsightedness,  but  it  is  only  apparent,  as  it  is  due 
to  a  spasm  of  the  muscle  of  accommodation,  which  the  patient 
overlooks.  As  soon  as  the  muscle  is  paralyzed  by  atropin  this 
apparent  shortsightedness  disappears. 

(5)  The  above  are,  however,  but  infrequent  causes  of  myopia. 
The  vast  majority  of  cases  of  every  degree  depends  not  upon  the 
anomalies  of  refraction,  but  upon  the  fact  that  the  retina  lies  back 
of  the  focus  of  the  lens  (see  Fig.  5,  c).  In  myopia  of  a  high  degree 
a  lengthening  of  the  globe  is  so  noticeable  as  to  be  apparent  in  life 
to  the  uneducated  observer,  and,  of  course,  the  fact  of  this  increase 
in  length  has  been  time  and  time  again  demonstrated  on  the  cada- 
ver. This  form  of  shortsightedness  is  called  axis-myopia,  in  con- 
tradistinction to  the  much  less  frequent  curvature  myopia. 

Lately  Fukala  has  advanced  the  view,  with  very  good  support,  too,  that  the  highest 
degree  of  shortsightedness  depends  upon  both  the  increased  length  of  the  globe  and  in- 
creased refractive  power  of  the  lens ;  he  supposed  also  that  ordinary  shortsightedness 
has  as  a  cause  some  change  in  the  lens  as  well  as  in  the  length  of  the  globe.  This  much 
at  least  is  certain,  that  myopic  eyes  have  been  found  which  must  have  had  the  unheard- 
of  length  of  42  vi?)i.  (!  !)  if  that  were  the  only  explanation  of  the  trouble. 

The  next  step  is  to  get  a  measure  for  shortsightedness  and  from 
it  to  form  a  rule  by  means  of  which  this  measure  can  be  applied 
to  any  given  case. 

Shortsightedness  is  manifestly  greater  in  proportion  as  the  retina 
lies  behind  the  focal  point  of  the  optical  system.  In  other  words, 
— a  shortsighted  eye  being  one  in  which  divergent  rays  proceeding 
from  the  point  R  and  passing  through  the  optical  system  form  an 
image  on  the  retina, — it  is  obvious  that  shortsightedness  is  the 
greater  the  nearer  the  point  R  lies  to  the  eye.  This  point  R  is  called 
the  far  point  {punctum  remotuin)  of  the  eye.  Shortsightedness  is 
small  if  R  is  a  long  way  off;  it  is  large  if  R  is  near;  that  is,  M  is 
inversely  proportional  to  the  distance  of  the  far  point. 

The  ophthalmic  formula  is  as  follows  :  M  =  .  Here  M  sig- 
nifies the  myopia  or  shortsightedness,  r  the  distance  of  R  from 
the  anterior  principal  point.  It  is  a  matter  of  indifference  how 
this  distance  is  measured.  Convenience  and  simplicity  have  finally 
settled  on  the  meter  as  the  unit  of  measure,  consequently  that  eye 
has  a  M  of  I  when  its  far  point  lies  at  i  w.  (M  =  y  =  i). 

Since  the  position  of  the  far  point  determines  the  degree  ot 
shortsightedness,  in  finding  this  far  point  we  at  once  measure  the 
M.  Take  any  object  that  requires  good  accommodation  to  perceive 


MYOPIA    AND    ACUTENESS    OF    VISION.  3 1 

it,  a  fine  point,  for  instance,  and  from  a  distance  bring  it  toward  a 
patient's  eye  till  he  can  see  it  clearly.  You  have  now  found  the 
far  point  of  this  eye.  Such  a  simple  expedient  is  often  resorted  to, 
but  its  general  application  has  one  great  disadvantage.  Print,  to 
be  read  at  a  moderate  distance,  accurately  and  with  absolutely  cor- 
rect accommodation,  must  be  very  small,  but,  unfortunately,  fine 
print,  in  spite  of  perfect  accommodation,  cannot  be  easily  read  be- 
yond a  certain  distance.  Therefore  in  practice  we  must  use  print 
of  different  sizes  for  each  particular  distance.  Since  this  is  hardly 
convenient,  we  generally  resort  to  another  method  of  measurement, 
which  depends  on  the  fact  that  by  introducing  a  concave  lens 
into  parallel  rays  (rays  from  infinity)  we  can  give  them  such  a 


Fig.  6. — Measurement  of  Shortsightedness  by  a  Neutralizing  Concave  Lens. 

divergence  that  they  form  an  image  on  the  retina  of  a  myopic 
eye. 

Fig.  6  illustrates  this  method.  In  i  is  a  section  of  a  myopic  eye 
on  whose  cornea  a  pencil  of  parallel  rays  falls.  This  pencil  comes 
from  a  point  of  light  to  the  left  lying  on  the  axis  at  infinity.  Imag- 
ine these  rays  extended  to  the  principal  plane,  H  H,  and  prolonged 
to  the  focal  point,  /  ".  (These  lines  are  dotted  at  first  to  indicate 
that  in  the  anterior  of  the  eye  the  path  of  the  rays  is  in  reality  differ- 
ent from  that  in  the  figure.)  From  /  ",  the  posterior  focus,  the  rays 
diverge  again  and  consequently  form  upon  the  retina  in  the  place 
of  an  image  a  mere  light  spot,  which  is  round  if  the  pupil  is  round. 
Now  then,  by  putting  a  concave  lens  before  the  eye  we  see,  in  ii, 
that  the  rays  strike  the  cornea  divergently  and  can  be  made  just  di- 
vergent enough  to  appear  to  come  from  R  (the  far  point) ;  they  there- 
fore form  an  image  on  the  retina  and  not,  as  before,  at  the  focus,/". 


32  THE    FUNCTION    TESTS. 

Without  farther  explanation,  it  is  evident  that  the  same  thing  can 
be  accomplished  with  concave  lenses  of  different  focal  lengths  ac- 
cording as  one  approaches  or  withdraws  the  point  R.  If  now  the 
concave  lens  is  so  close  to  the  shortsighted  eye  that  the  distance 
between  the  concave  lens  and  the  principal  plane  can  be  neglected, 
then  the  focal  length  of  this  ?ieutralizmg  concave  lens  will  be  exactly 
equivalent  to  the  distance  of  the  far  point  of  the  s ho?' t sighted  eye. 
The  reciprocal  value  of  the  focal  distances  of  the  concave  lens  is 
therefore  the  measure  of  the  myopia.  We  have  then  the  following 
rule  for  measuring  myopia  by  a  concave  lens  :  Let  the  patient  look 
at  some  object  at  infinity  (in  practice  6  w.),  hold  in  front  of  his  eye 
concave  lenses  of  gradually  increased  strength  (of  shorter  focal 
distance) ;  the  weakest  lens  with  which  the  shortsighted  person 
sees  this  object  distinctly  is  the  measure  of  the  distance  of  his  far 
point,  that  is,  of  the  myopia. 

In  doing  this  we  have  overlooked  two  conditions  not  yet  men- 
tioned ;  the  first  concerns  the  customary  nomenclature  of  the  lens 
with  respect  to  their  focal  distances,  the  second  concerns  the  im- 
portant question  as  to  how  we  are  to  know  that  the  patient  actually 
does  see  an  object  distinctly.  For  the  mere  statement  that  such 
is  the  case  is,  at  least  in  those  not  accustomed  to  close  observation, 
very  untrustworthy. 

The  lenses  used  by  the  oculist  for  estimating  refractive  condi- 
tions are  found  in  the  ordinary  test-case.  These  are  numbered, 
but  the  numbers  do  not  denote,  as  one  might  expect  or  as  was 
formerly  the  custom,  the  focal  distances,  but  their  reciprocal  values, 
that  is,  their  converging  (convex)  and  diverging  (concave)  power. 
For  the  sake  of  simplicity  we  have  adopted  Nagel's  proposal  to 
use  the  meter-lens,  i.  e.,  a  convex  lens  of  i  meter  focal  distance, 
the  converging  power  of  this  lens  being  called  a  Diopter,  denoted 
by  i.o  D.  Since  the  converging  power  of  a  lens  is  inversely  pro- 
portional to  its  focal  distance,  a  lens  of  2.0  D  strength  has  a  focal 
distance  of  0.5  (3^)  ;«.,  50  cm.\  a  lens  of  o.j  D  strength  has  a 
focal  distance  of  —  =  -^,  or  2  in.,  etc. 

When  lenses  were  distinguished  by  their  focal  distances  these  were  given  sometimes 
in  French,  sometimes  in  English  inches.  36  French  inches  =40  English  inches  =^  I 
m.  ;  or  0.36  Paris  inch  =  0.40  English  inch  =  I  cm.  If  we  wish  to  convert  diopters 
into  the  old  nomenclature  of  inches,  find  the  focal  distance  of  the  lens  in  centimeters 
and  translate  it  into  inches  thus  :  a  lens  of  ^.o  Z>  =  -  in.  =  -"^  cm.  •=  ^o  cm. ;  but  so 
cm.  is  equal  to  18  French  or  20  English  inches,  and  the  number  of  the  lens  would  be 


MYOPIA    AND    ACUTENESS    OF   VISION.  33 

y'y  or  ^\  respectively.  To  get  the  focal  distance  of  the  lens  in  the  old  inch  system, 
divide  the  36  French  or  40  English  inches  (  =  i  ;«.)  by  the  dioptric  strength  of  the  lens, 
thus  :  a  lens  of  2.0  Z>  =  2)  36  or  40,  =  18  or  20  inches.  Reverse  the  process  to  get 
from  the  old  nomenclature  into  the  new,  thus  :  a  number  ^'^j  English  ^  20)  40  =  2  ; 
a  ^^ij  is  a  lens  of  2.0  D. 

Concave  lenses  are  also  reckoned  in  diopters.  A  concave  lens  of 
I  in.  (negative)  focal  distance  has  a  divergent  power  of  I  diopter, 
or  is  — i.o  D.  If  we  find  in  any  case  that  vision  is  made  normal 
by  a  concave  lens  of — ;^.o  D,  then  -  ^  3,  that  is,  the  myopia  of 
that  eye  =  3  diopters  and  is  expressed  as  M  =  j.o  D. 

The  other  condition  not  yet  mentioned  concerns  some  expression 
for  the  acuteness  of  vision  (Vision  =  V)  under  proper  accommo- 
dative circumstances.  Naturally  the  vision  of  an  eye  is  better  the 
nearer  the  retinal  images  {r.y  and  -2,  Fig.  7)  of  two  points  (/i  and  p^ 
come  to  each  other  before  they  cease  to  be  distinguishable.  The 
measurement  of  the  distance  of  the  two  points,  -■^  and  -2,  can  be  ex- 


FlG.  7. 

Acuteness  of  vision  is  measured  by  the  smallest  angle  within  which  an 

object  is  recognizable. 


pressed  by  a  simple  proportion  composed  of  the  distance  of  the 
points  /i  and  p^  from  each  other,  of  the  distance  of  px  and  ^2  from 
the  nodal  point,  K,  and  of  the  distance  of  K  from  the  retina  ;  since 
this  last  distance  is  constant  (=  15  ;«;//.)  we  need  only  say  that  the 
size  of  -1  "2  is  directly  proportional  to  the  size  of />!  p^  and  inversely 
proportional  to  the  distance  of  px  p^  from  K ;  that  is,  the  size  of 
-1  TTj  is  proportional  to  the  "visual  angle"  at  which  /1/2  is  seen. 
The  formula  is  tz^  -k^  =  ^ ,  when  L  =  the  length  of  the  object,  /i  pz, 
and  d  =  its  distance  from  K ;  the  smaller  -^  tz^  is,  the  sharper  is 
vision ;  that  is,  V  is  inversely  proportional  to  -1  -2,  so  the  formula 
becomes  V  =z  y. 

In  putting  this  into  practice  we  determine  V  by  means  of  letters 

of  different  lengths  placed  at  certain  distances  and  by  finding  the 

smallest  letters  that  can  at  any  distance  be  distinctly  recognized. 

Experiment  has  shown  that  ^/le  normal  eye  recognizes  letters  five 

3 


34  THE    FUNCTION   TESTS. 

times  as  long  as  they  are  broad  wlieii  they  are  at  such  a  distance  that 
they  cati  stnke  the  eye  at  a  visual  angle  of  j  nmiutes.  The  vision 
of  such  an  eye  is  arbitrarily  put  down  as  /.  Now,  to  be  able  to 
compare  with  the  least  trouble  the  vision  of  any  eye  with  that  of 
the  normal,  we  use  letters  that  we  already  know  can  be  recognized 
at  the  proper  distance  by  eyes  whose  V  =  /,  in  other  words,  at 
such  a  distance  that  their  length  appears  to  fill  the  angle  of  5 
minutes  and  their  breadth  the  angle  of  /  minute;  this  distance 
expressed  in  meters  is  called  D.  Since  this  D  is  necessarily 
directly  proportional  to  the  size  of  the  letter,  we  can  express  the 
size  of  the  letter  by  D.  The  formula  for  visual  acuity  then 
becomes  the  following  generally  used  one:  F=  j^-,  or  in  words, 
the  vision  of  an  eye  is  equal  to  the  distance,  d,  of  the  smallest 
recognizable  letter  divided  by  that  distance,  D,  in  which  a  normal 
eye  (with  F=  /)  ought  to  read  the  same  letter.  For  example, 
the  smallest  letter  that  a  patient  can  read  with  one  eye  at  6  in.  dis- 
tance is  an  E  whose  D  =  Jo  w«.  (ought  to  be  read  at  jo  m.)  ;  then 

the  V  oi  this  eye  =  —  =     ,     If  with  the  other  eye  he  can  read 
^  30         5  ^ 

at  6  m.  a  letter  whose  0=4,  then  the  V  of  this  eye  =      =  "^ , 

better  than  normal. 

To  estimate  V\we  make  use  of  letters,  as  has  been  already  said  ; 
since  if  the  patient  recognizes  the  letters  it  is  proof  enough  that  he  ' 
recognizes  their  form.  In  case  the  patient  cannot  read  we  use  hooks, 
n  U  C  IJ-I  rn  E,  and  ask  him  to  tell  us  whether  the  lines  run  up  or 
down  or  to  the  right  or  left.  There  are  test-cards  published  with 
rows  of  letters,  figures,  and  hooks  of  different  sizes ;  every  row  is 
marked  with  a  figure  which  tells  us  the  D  of  that  particular  size. 
Each  card  generally  has  a  letter  with  D  ^  <5o  at  the  top  and  D  = 
<5  or  D  =  5  at  the  bottom. 

Although  we  have  supposed  that  a  healthy  eye  has  F=  /,  the 
statement  must  be  modified  to  some  extent,  for  it  is  obvious  that 
not  all  healthy  eyes  can  have  the  same  acuity  of  vision.  As  /^de- 
pends not  only  upon  the  quality  of  the  dioptric  apparatus,  but  also 
upon  that  of  the  retina,  of  the  optic  nerve,  and  of  the  brain,  it  is 
easy  to  imagine  personal  differences  within  physiological  limits.  V 
is  not  always  /  in  the  normal  eye.  In  youth  it  is,  as  a  rule,  better 
than  I.      f^=  T  or  even  =  —r-  is  not  uncommon,  and  there  have 

been    reports  of    F  =   r-,  6^    times    the    normal !     This   hap- 


MYOPIA    AND    ACUTENESS    OF    VISION.  35 

pened  among  the  Kalmucks,  With  increasing  years  visual  acuity 
gradually  declines.  This  is,  as  a  rule,  the  result  of  small  opacities 
in  the  lens  or  of  other  such  pathological  changes ;  but  even  if 
there  is  nothing  of  this  nature,  the  acuteness  of  vision  of 
the  old  is  less  than  that  of  the  young.  How  great  this  physio- 
logical defect  in  the  aging  eye  on  the  average  is,  cannot  be  stated 
without  further  investigation. 

Bonders  and  his  pupil,  de  Haab,  assert  that  from  the  thirtieth  year  on  visual  acuity 
sinks  one-tenth  every  ten  years,  and  between  the  fiftieth  and  sixtieth  years  even  two- 
tenths,  till  the  visual  acuity  in  the  eightieth  year  is  only  one-half  the  normal.  This 
"  Haab's  law  "  has  not  withstood  the  test  of  investigation.  H.  Cohn  has  examined  ico 
persons  more  than  sixty  years  of  age  to  find  that  the  decrease  in  visual  acuity  in  the 
normal  eye  was  extremely  slight,  and  confined  to  the  tenth  decade.  Boerne  and  Walther 
examined  400  persons  to  find  that  in  the  healthy  eye  there  was  a  slight  and  uniform  de- 
crease in  acuity  from  the  fortieth  year  on  ;  but  that  in  the  senile  eightieth  year  acuity  of 
vision  was  still  |. 

To  determine  the  near  point  of  V  we  use  printed  test-cards  that 
must  be  read,  not  merely  spelled  out  by  the  patient.  This  print  is 
also  furnished  in  different  sizes,  marked  with  figures  to  designate 
at  what  distance  the  eye  with  V  =  i  ought  to  read  them.  This  is 
the  case  in  the  publications  of  Snellen  and  Schweigger,  but  not  in 
the  popular  one  of  Jaeger. 

If  a  patient's  V\s  so  poor  that  he  cannot  read  letters,  let  him  try 
to  count  fingers  spread  out  in  front  of  a  dark  background  (say  the 
physician's  black  coat).     Fingers  are  about  equal  to  letters  with 

2 

D  =  60,  so  that  a  patient  who  can  read  fingers  at  2  in.  has  V=^, 
If  he  cannot  count  even  fingers,  try  the  movement  of  the  whole 
hand.  The  smallest  degree  of  V  can  only  distinguish  light  from 
darkness. 

To  read  a  connected  word  close  to  the  eye  is  not,  without  some 
further  explanation,  comparable  to  the  ability  to  distinguish  letters 
by  their  form,  even  assuming  the  condition  fulfilled  that  individual 
letters  appeared  in  one  case  as  well  as  in  the  other  at  the  same 
visual  angle.  In  a  word  of  several  letters  each  letter  need  not  be 
recognized  by  its  form  ;  it  may  be  guessed  by  the  connection  ;  it 
not  infrequently  happens  that  the  proper  letter  is  supplied  when  in 
reality  an  improper  one  was  in  its  place  by  a  misprint.  Moreover, 
reading  may  be  made  difficult  by  the  fact  that  the  letters  are  placed 
too  close  to  each  other.  It  is  not  scientific  to  make  the  test  depend 
on  these  two  circumstances  alone. 


36  THE    FUNCTION    TESTS. 

Several  investigators,  and  recently  Ciuiller)',  have  shown  that  Snellen's  method  of  esti- 
mating visual  acuity  is  neither  practically  nor  theoretically  free  from  deception.  It  is  a 
daily  experience  that  not  all  the  letters  of  one  row  can  be  read  at  the  same  distance ;  the 
letters  E,  R,  B^  for  example,  require  the  observer  to  be  closer  to  them  than  do  the  equally 
large  but  simpler  constructed  letters  /',  T,  A,  V.  Moreover,  it  has  been  theoretically 
suggested  that  the  visual  acuity  of  an  eye  is  inversely  proportional  to  the  surface  area  of 
the  retinal  image  of  an  object  and  not  to  the  visual  angle  at  which  it  appears. 

The  first  source  of  deception  must  be  acknowledged,  and  in  recent  editions  of  test- 
cards,  especially  Schweigger's,  allowance  has  been  made  for  it.  It  can  be  altogether 
avoided  if  hooks  are  used  instead  of  letters,  a  test  method  that  for  other  reasons  has  been 
recommended  by  many  ophthalmologists.  The  second  source  of  deception  I  consider 
of  no  value.  The  idea  that  a  letter  is  the  easier  recognizable  the  greater  the  area  of  its 
retinal  image,  has  not  been  proved  even  by  its  advocate,  and  facts  are  against  it.  In- 
deed, the  opposite  is  the  true  view,  for  the  principle  of  the  estimation  of  visual  acuity 
depends  with  logical  necessity  upon  the  interval  between  two  luminous  points,  only  one 
dimension  being  considered,  therefore.  The  proposition  that  the  area  of  the  retinal  image 
is  a  determinative  factor  must  rest  on  the  implied  notion  that  retinal  areas  separated  by  a 
space  are  of  mutual  support  to  each  other  in  vision.  According  to  my  investigations 
this  notion  is  correct  as  far  as  concerns  light  and  color  sensations,  but  in  the  recognition 
of  objects,  or,  in  other  words,  in  reference  to  space  perception,  there  is  no  mutual  support 
of  separate  retinal  areas,  or  it  is  present  in  a  degree  not  worth  mentioning. 

After  this  digression  let  us  return  to  the  problem  of  measuring 
myopia  by  means  of  lenses. 

The  patient  is  placed  with  his  back  to  the  window ;  the  wall 
opposite  should  be  well  lighted  and  on  it  at  ^X.o  6  in.,  according 
to  the  size  of  the  room,  should  hang  the  test-cards.  They  can- 
not, of  course,  be  placed  at  infinity,  but  calculation  shows  that 
rays  from  6  nt.  or  even  4  m.  are  so  slightly  divergent  in  passing 
through  a  pupil  only  a  few  millimeters  in  diameter,  that  we  can 
neglect  this  fact  without  noticeable  error  and  consider  the  rays 
practically  parallel. 

A  pupil  of  4  mm.  diameter  receives  from  a  luminous  point  at  4000  mm.  rays  that  enter 
at  an  angle  of  only  3  minutes.  This  angle  is  about  the  x5o*^  ^^  ^^^  angle  repre- 
sented in  Fig.  J,  p.  jj.  If  one  tries  to  imagine  such  an  angle  one  can  easily  see  that  it 
is  practically  neglectable.  The  same  conclusion  can  be  reached  thus  :  a  luminous  point  at 
infinity  has  its  image  at  the  focus  of  the  lens  ;  one  at  4000  mm.  has  its  image  at  0.07  mm. 
behind  the  focus  ;  the  rays  in  this  case  therefore  forming  an  image  practically  at  the  focal 
point.  Or  we  can  easily  allow  for  the  error  arising  from  the  fact  that  the  test-card  is 
not  at  infinity,  since  a  patient  accommodating  for  the  test-card  at  5  m.  has  an  error  of 
only  —  =  o..?  Z>,  an  amount  so  small  that  it  is  scarcely  to  be  measured  by  any  lens  in  the 

ordinary  test  case.     At  4  m.  this  error  is  just  — -  =;  o.  2j  D. 

4 

Now  ask  the  patient  to  read  without  glasses.  If  he  is  short- 
sighted he  can  recognize  only  the  largest  letters.  For  example,  he 
is  found  to  read  without  glasses  at  4  in.  only  letters  that  ought  to 


HYPERMETROPIA.  37 

be  read  at  jo  {D  =  jo)  or  even  at  60  {D  =  60)  m.  Then  give 
him  a  concave  lens,  beginning  with  the  weakest  and  increasing  till 
the  strongest  is  found  that  improves  his  vision.  The  weakest  con- 
cave lens  with  which  he  sees  best  measures  the  myopia  present. 
A  stronger  lens  cannot  be  used,  for  in  that  case  there  would  be  an 
effort  at  accommodation  to  overcome  the  extra  divergence,  and 
this  lens  would  then  indicate  the  myopia  plus  any  additional  but 
not  yet  measured  accommodation.  Atropin  would,  of  course, 
paralyze  this  accommodation,  so  that  a  paralyzed  (atropinized) 
eye  would  see  less  distinctly  as  soon  as  too  strong  a  concave  lens 
were  used. 


4.  HYPERMETROPIA,  H. 

A  second  refractive  condition  of  an  eye  is  called  Hypermetropia, 
or  farsightedness,  a  term  not  quite  intelligible  without  further 
explanation.  A  hypermetropic  eye  is  not  able  without  accommo- 
dation to  produce  on  the  retina  an  image  from  a  luminous  point  at 
infinity  or  theoretically  this  side  of  infinity  ;  and  this  image  can  be 
formed  on  the  retina  only  in  case  the  homocentric  pencil  of  rays 
falls  upon  the  cornea  convergently.  Since  all  objects  of  the  outer 
world  send  either  parallel  or  divergent  rays  to  the  cornea,  a  hyper- 
metropic eye  must  be  unable,  when  not  accommodating,  to  see 
either  near  or  far  objects.  If,  therefore,  the  hypermetrope  can  read 
and  write  and  accomplish  other  work,  the  credit  of  seeing  larger 
objects  at  any  rate,  even  though  their  retinal  images  are  indistinct, 
must  be  due  to  the  power  of  accommodation. 

If  in  hypermetropia  rays  of  a  certain  convergence  meet  at  the 
retina,  then  rays  parallel  at  the  cornea  must  form  an  image  behind 
the  retina.  An  eye  is  therefore  hypermetropic  when  its  focal  point 
lies  behind  the  retina. 

The  fact  that  ia  hypermetropia  the  posterior  focal  point  and  retina  do  not  coincide  can 
be  explained  in  several  ways. 

(l)  Let  us  consider  the  dioptric  apparatus.  Is  it  possible  that  too  low  a  refractive 
index  of  the  transparent  media  of  the  eye  explains  this  increase  in  focal  distance  ?  This 
is  not  absolutely  impossible.  The  hypermetropia  of  the  new-born  and  children  may 
partly  at  least  depend  upon  insufficient  density  of  the  nucleus  of  the  lens  ;  nothing  exact 
is  known  about  this,  however,  and  it  is  not  even  an  undisputed  fact  that  children  are  born 
hypermetropic,  or  are  changed  during  youth  to  hypermetropes  of  a  lesser  degree  or  to 
emmetropes  or  to  myopes.  Moreover,  there  is  the  apparently  contradictory  fact  that 
hypermetropia  sometimes  depends  upon  too  great  a  refractive  index.  To  understand  this 
we  must  rememl)er  one  fact  in  the  anatomy  of  the  lens  ;   the  human  crystalline  lens  has  a 


38 


THE    FUNCTION    TESTS. 


stratified  structure,  the  middle  part,  the  so-called  nucleus,  l)eing  surrounded  by  strata  like 
an  onion,  each  stratum  having  a  lesser  density  than  the  one  lying  next  to  it  internally, 
and  a  greater  density  than  the  one  next  to  it  externally.  The  nucleus  is  therefore  to  be 
considered  as  surrounded  by  concavo-convex  layers  with  refractive  indexes  decreasing 
from  within  outward.  Fig.  8  shows  the  hollow  side  of  each  layer  with  a  smaller  radius 
of  curvature  than  that  of  the  convex  side ;  consequently  each  layer  considered  by  itself, 
that  is,  as  having  the  same  medium  in  front  of  and  behind  it,  acts  as  a  diverging,  not  as 
a  converging  lens,  the  divergence  being  greater  the  higher  the  refractive  index  is.  It  is 
therefore  clear  that  the  converging  power  of  the  whole  lens  will  be  the  greater  the  less 
the  refractive  index  of  the  periphery  of  the  lens  is.  Now  during  life  the  lens  undergoes 
changes  which  can  be  explained  by  the  deposit  of  new-formed  lens  cells  in  the  region  of 
the  lens  equator  and  by  the  so-called  nuclear  sclerosis.  The  lens  nucleus  becomes  thicker 
and  denser  with  increasing  age.  but  larger  as  well,  because  the  peripheral  layers  become 
more  and  more  like  the  nucleus,  or  they  may  melt  completely  into  it.  An  increased 
density  of  the  periphery,  or,  what  is  the  same  thing,  a  melting  together  of  periphery  with 
nucleus,  will  lower  the  converging  power.  In  can  be  seen* 
therefore,  that  the  physiological  changes  of  age  in  the  lens  peri- 
phery are  able  to  increase  the  focal  distance  of  the  eye,  or,  for 
example,  an  emmetropic  eye  may  become  hypermetropic. 

Hypermetropia  can  also  be  produced  by  too  great  a  refrac- 
tive index  in  the  vitreous ;  for  luminous  rays  in  passing  out  of 
the  lens  into  the  vitreous  are  refracted  convergently  proportional 
to  the  difference  between  the  refractive  indexes  of  the  two  media. 
If  the  refractive  index  of  the  vitreous  increases  and  thereby  ap- 
proximates that  of  the  lens,  then  the  converging  power  of  the 
eye  must  decrease.  Such  a  case  has  been  described  by  Landolt. 
A  woman  with  diabetes  had  at  the  same  time  a  moderate  hyper- 
metropia that  disappeared  when  the  sugar  disappeared  and  re- 
turned with  the  return  of  sugar.  Landolt' s  explanation  is,  that 
while  sugar  was  present  the  vitreous  became  sugary,  its  refrac- 
tive power  being  thus  increased. 

(2)   Hypermetropia  can  be  caused  by  too  weak  a  curvature 
of  the  refractive  surfaces  in  the  cornea  and  lens.     The  cornea 
can  be  flattened  by  scars,  particularly  those  made  at  its  edge  in 
operations ;  the  cornea  is,  however,  not  only  flattened,  but  also 
loses  some  of  its  spherical  shape,  thus  producing  the  condition 
cSi  astigmatism,  which  we  shall  discuss  later,  and  which  has  such  an  influence  on  vision 
that  in  comparison  the  hypermetropia  dependent  on  corneal  flattening  is  of  minor  signifi- 
cance. 

A  pure  hypermetropia  does,  however,  result  rather  frequently  from  a  flatness  of  the 
lens.  It  has  been  mentioned  that  during  life  the  lens  undergoes  changes  in  density 
(which  implies  an  increased  refractive  index) ;  the  same  is  true  of  its  form,  which  implies 
an  increased  surface  curvature.  The  lens  of  the  new-bom  has  an  anteroposterior  diame- 
ter oi  4.0  to  4.^  mm.  and  a  breadth  of  6.0  mm.  ;  the  mature  lens  has  also  anteroposterior 
diameter  of  4.0  to  4.^  mm.,  but  is  g.o  to  lo.omm.  in  breadth.  This  shows  that  the  lens 
in  youth  has  a  stronger  curvature,  in  age  a  weaker  one.  We  can  therefore  ascribe  the 
frequent  change  in  advancing  life  from  emmetropia  to  hypermetropia  both  to  increasing 
thickness  in  the  cortex  and  to  a  flattening  of  the  lens  itself. 

Naturally  the  hypermetropia  is  very  intense  when  the  lens  is  altogether  lacking.  This 
is  the  case  in  lensless,  "aphakic"  eyes  the  result  of  congenital  conditions,  of  injuries,  or 


Fig.  8. 
The  menisci  bounded  by 
the  lines  ab  and  a'b', 
and  by  the  arcs  aa  ai  d 
bf ,  have  a  smaller  re- 
fractive index  than  the 
nucleus,  but  a  greater 
index  than  the  two 
outer  menisci,  c'c  bb'. 


HYPERMETROPIA.  39 

of  cataract  operations.     In  an  aphakic  eye  otherwise  normal  the  focus  lies,  as  has  been 
said  (/.  2j),  nearly  /  cm.  behind  the  retina. 

Although  there  are  cases  of  hypermetropia  due  to  faults  in  the 
lens,  they  are  infrequent  in  comparison  with  that  kind  of  hyperme- 
tropia depending  on  a  lack  of  coincidence  of  focus  and  retina  in  an 
eye  that  is  in  every  respect  normal. 

(3)  Hypermetropia  is  generally  due  to  the  fact  that  the  eye  is  too 
short.  Anatomical  measurements  have  established  this  fact,  and  in 
pronounced  cases  it  can  even  be  recognized  in  the  living  body.  If 
a  hypermetrope  is  asked  to  turn  his  eye  strongly  inward,  the  globe 
becomes  visible  up  to  the  equator,  and  the  sharp  curve  (its  small 
size,  therefore)  is  quite  apparent ;  this  is  particularly  noticeable  upon 
examining  a  myopic  eye  at  the  same  time,  when  the  oval  shape  of 
the  latter  and  its  lesser  curvature  toward  the  equator  come  out  in 
distinct  contrast. 

The  degree  of  hypervietropia  is  obviously  measured  by  the  con- 
vergence which  must  be  given  to  the  luminous  rays  at  the  cornea 
in  order  to  form  an  image  on  the  retina.  That  point  toward  which 
rays  must  tend,  when  passing  through  the  refractive  media  of  the 
eye,  in  order  to  form  an  image  on  the  retina,  is  called  the/^r  point 
of  that  eye  {R  in  Fig.  g) ;  but  since  the  convergence  of  rays  is  esti- 
mated by  the  position  of  the  far  point,  we  can  say  that  hypermetro- 
pia is  inversely  proportional  to  the  distance  of  the  far  point,  or 
H  ^  ,  not  forgetting,  of  course,  that  in  this  case  the  far  point  is 
virtual  or  negative  and  lies  behind  the  eye.  In  accordance  with 
the  explanation  in  the  previous  section,  it  is  understood  that  we 
measure  r  in  meters,  and  that  therefore  //"=  -f-  /  is  the  hypermetro- 
pia of  an  eye  whose  far  point  lies  /  m.  behind  the  principal  plane  of 
that  eye. 

The  degree  of  hypermetropia  is  found  by  selecting  that  convex 
lens  which  gives  to  parallel.rays  the  convergence  necessary  to 
focus  them  at  the  far  point  of  the  eye.  But  it  is  obvious  that 
convex  lenses  of  different  strengths  can  do  this  so  long  as  attention 
is  paid  only  to  making  the  focus  of  the  lens  identical  with  that  of 
the  eye.  In  Fig.  9,  for  example,  let  5  5  be  a  lens  whose  focus  is  at  R, 
that  is,  a  lens  which  converges  parallel  rays  to  a  focus  at  R.  If  we 
place  the  lens  further  from  the  eye  at  A  (toward  the  left),  then  its  focal 
distance,  A  R,  would  have  to  be  much  longer,  and  its  refractive  power 
much  less  than  that  of  a  lens  at  6"  5.    We  must  therefore  have  a  defin- 


40  THE    FUNCTION   TESTS. 

ite  place  at  which  to  put  the  lens.  Theoretically  this  would  be  at 
the  principal  plane  of  the  eye,  but  since  this  is  obviously  impossible, 
the  rule  has  been  established  to  put  the  lens  as  close  to  the  cornea 
as  possible ;  by  doing  this  the  distance  of  the  lens  from  the  princi- 
pal point  of  the  eye  can  be  neglected,  and  the  distance  from  S  S  to 
R  can  be  considered  equal  to  the  distance  of  the  far  point  (punctum 
remotum)  of  the  hypermetropic  eye,  which  is,  exactly  speaking,  only 
the  distance  from  R  to  the  principal  plane.  Now  then,  that  lens 
which,  placed  close  to  the  patient's  eye,  makes  parallel  rays  con- 
verge to  an  image  at  the  far  point,  R,  or,  in  other  words,  which 
enables  that  eye  to  see  distinctly,  is  the  lens  which  measures  the 
hypermetropia,  assuming,  of  course,  that  the  patient  makes  no  effort 
at  accommodation,  a  condition  which  is  not  as  a  rule  realized. 

The  hyperope  who  can  see  distinctly  objects  at  a  distance  (in- 
finity) only  when  he  shortens  the  focal  distance  of  his  eye  by  the 
help  of  his  accommodating  power,  is  so  accustomed  to  this  act 


Fig.  9.— Measuke  op  HvpsKMBTKonA  bt  Mbams  of  a  Nkutiiausiiic  Lkms. 

that  he  brings  it  into  play  even  when  the  converging  lens  held 
before  his  eye  makes  this  act  superfluous.  Thus  it  happens  that 
hyperopes  accept  weak  lenses  and  refuse  strong  ones,  although  it 
may  be  proven  later  on  that  the  stronger  was  the  prop>er  lens  to 
correct  the  hypermetropia  Hypermetropia  is  therefore  partly  volun- 
tary [manifest)  and  partly  involuntary  {latent)  as  a  rule. 

To  demonstrate  as  nearly  as  possible  the  total  hyperopia,  pro- 
ceed as  follows :  Let  the  patient  read  the  letters  on  the  test-card  as 
far  as  he  can  without  glasses ;  then  have  him  shut  the  eye  under 
examination ;  ^  when  the  eye  is  shut  the  muscle  of  accommodation 
is  relaxed ;  now  place  a  convex  lens  in  front  of  his  eye  and  let  him 
then  open  it.  This  proceeding  reduces  to  a  minimum  the  effort  to 
accommodate,  corresponding  to  the  strength  of  the  lens  used. 
Continue  thus  to  keep  the  eye  shut  at  every  change  oflens,  and  as 


^  It  is  tmderstood  that  only  one  eye  is  examined  at  a  time,  the  other  being  ckxed 
meanwhile. 


KANGE  OF   ACCOMMODATION   AND  FltBSftTOnA.  ^I 

a  rule  the  greater  part  of  the  manifest  h\*peropai  will  be  overcouic. 
Only  in  \-er>-  young  persons   is  the  opposite  usoiktty  the  c*se. 

(Concerning  the  influence  of  age,  see  "  H\-perc^a.**>  If  the  puttent 
continuously  wears  the  lens  corresponding  to  his  maniie^  ^yp^^ 
opia,  a  second  test  can  be  made  after  a  few  weeks^  and  probabh* 
by  this  time  the  former  latent  hyperopia  will  now  be  changed  to  a 
manifest  h\-peropia.  for  the  less  frequent  claim  on  the  invcJuntan^ 
effort  to  accommodate  has  materially  relaxevl  the  "sj>asm  of 
accommodation  "  which  was  there  before. 

To  estimate  the  total  hypermetrv»pia  at  the  first  trial  we  must 
paralyze  the  muscle  of  acconmiodation  by  atropin  or  hon\atn>pin. 
This  is  not  to  be  indiscriminately  resorted  to,  for  atropin  paralyses 
not  only  the  musculus  ciliaris  (the  muscle  of  accomnuxlation)  but 
also  the  sphincter  iridis.  The  result  is  a  strong  dilatation  of  the 
pupil  and  an  unpleasant  dazzling,  preventing  the  patient  fivm  doing 
any  work  close  to  the  ex'e.  These  disadvantages  are  particularly 
distressing  after  atropin.  the  effect  of  which  scarcely  disappears 
even  after  eight  days,  while  the  effect  of  a  moderate  dcvse  of  homa« 
tropin  may  have  nearly  passed  off  within  a  day  or  so.  It  must  be 
remembered,  too,  that  atropin  while  jxiralyzing  the  muscle  of 
accommodation  may  destroy  its  prv^per  and  normal  tone,  so  that 
a  hypermetropia  may  be  produced  that  in  reality  does  not  exist. 

5.   RANGE  OF  ACCOMMODATION  AND   PRKSBYOriA. 

It  has  been  shown  that  the  tar  jx^int  of  an  emmetropic  eye  lies 
at  infinity,  that  of  a  myopic  eye  at  a  finite  distance  before,  that  of  a 
hyperopic  eye  at  a  finite  distance  behind,  the  retina.  Kvery  eyt, 
no  matter  what  its  refractive  condition  is,  can,  with  the  help  of 
accommodation,  see  objects  nearer  than  its  far  point.  The  nearest 
point  which  an  eye  can  see  when  its  total  accommodation  is  called 
into  play,  is  called  the  fuutr  /V»»>r/ (punctum  proximum),  A^in  f{^, 
10.     Tfw  dio/^tnc  value  of  that  f/tanj^t-  tvhich  an  *r  '    iyts  in 

accommoiiatifti^  from  its  far  f>oint  to  its  ntar  point  is lanj^ 

of  accommodation  and  is  designated  by  A. 

We  must  now  determine  how  to  measure  this  change  which  an 
eye  undergoes  in  accommoilating  from  any  point,  a,  to  a  nearer  point, 
/k     a.  Fick  '    and  later  Donders  ^  proposed  as  a  measure  of  this 


'  ••  Die  medicinische  rhysik."     Hriuimchweig.     S.  306.     1856. 
*  Anh.  /',  0/>ht'i      i\   ,  I,  S.  305.     1S5S, 


42 


THE    FUNCTION    TESTS. 


accommodation  the  strength  of  that  convex  lens  which  would 
adjust  an  eye  to  the  nearer  point  without  effort  on  its  own  part. 
This  proposal  has  been  since  then  universally  adopted.  Suppose 
a  convex  lens  placed  in  the  principal  plane  of  the  eye;  then  its 
refractive  strength  and  with  it  also  the  range  of  accommodation 
can  be  expressed  by  the  formula  A  =  —^ -^} 


/ 


The  formula  A  =z    '  '    is  derived   from   the    formula    in  physics   used  for  lens 

'      1      '  ,  or,  translated  into  words,  the  reciprocal  value  of  the  focal  distance  of  a 
*i      b 
lens  (its  refractive  strength)  is  equal  to  the  reciprocal  value  of  the  distance  of  the  object 

plus  the  reciprocal  value  of  the  distance  of  the  image  from  the  lens.  This  will  be  under- 
stood from  Fig.  lo.  M  denotes  a  myopic  eye  whose  principal  plane  is  mai-ked  //  H ; 
the  far  point  is  F  and  the  near  point  N.  Imagine  a  convex  lens,  S  S,  placed  in  the  principal 
plane,  its  strength  being  just  enough  to  make  divergent  rays  from  A^  convergent,  so  as  to 
appear  to  come  from  F.  In  the  above  formula,  iVnow  is  the  same  as  a,  the  distance  of 
the  object,  and  7^  the  distance  of  the  image,  b  ;  but  since  7^  does  not  lie  in  the  direction 


'I      ;.^»tigv^^^— ::v;v. 


Fig.  jo. — Mhasurhmknt  of  the  Range  of  Accommodation  by  a  Convex  Lens. 

of  the  luminous  rays  but  in  a  prolongation  backward,  the  image  is  in  this  formula  virtual, 
and  — i^must  be  substituted  for  b.     The  formula  then  becomes 


/ 


—  A 


N    ^  —F 


I 

7/ 


Let  us  now  apply  the  general  formujaof  the  range  of  accommoda- 
tion to  particular  refractive  cases.  The  far  point  in  emmetropia  lies 
at  infinity,  oo  ;  then  —p  =  O.  The  far  point  in  hypermetropia  lies  be- 
hind the  eye  and  is  negative  ;  -y  becomes  ~:^^.  If  the  minus  sign 
be  placed  in  front  of  the  equation  it  indicates  that  the  range  of  accom- 

If  we  remember,  more- 


modation  in  hypermetropia   =  -^  +  -^ 


N  and  F  in  this  formula  signify  Near  and  Far  points. 


RANGE    OF    ACCOMMODATION    AND    PRESBYOPIA.  43 

over,  that  the  hypermetropia  of  an  eye  is  equal  to  the  reciprocal 
value  of  the  distance  of  its    far  point  (  =    „-  ),  and  the  myopia  of 

another  eye  =  -^  then  we  can  express  A  for  each  particular  case 
in  the  following  manner  : — 

Ac)  =  -^ 

^W  =  ^  +  //, 

or,  in  words  :  The  range  of  accommodation  of  an  emmetropic  eye 
is  equal  to  i  divided  by  the  distance  of  its  near  point ;  the  range 
of  accommodation  of  a  myopic  eye  is  equal  to  i  divided  by  the 
distance  of  its  near  point  minus  its  myopia;  the  range  of  accommo- 
dation of  a  hypermetropic  eye  is  equal  to  i  divided  by  the  distance 
of  its  near  point  plus  its  hypermetropia. 

How  do  we  get  the  near  point  of  an  eye  ?  The  simplest  method 
is  obviously  to  approach  a  test-type  to  the  eye  till  it  can  no  longer 
be  read ;  the  shortest  distance  from  the  principal  plane  at  which  a 
letter  can  be  read  must  be  the  near  point,  but  since  large  type  can 
be  read  by  an  eye  even  when  it  is  not  exactly  accommodated  for 
it,  we  must  select  a  letter  suitable  to  the  supposed  near  point  and 
proportionate  to  the  estimated  acuteness  of  vision.  Suppose  we 
find  that  an  eye  can  read  Snellen  0.5  (that  is,  Snellen's  type  which 
a  normal  eye  reads  at  0.5  ;;/)  at  even  15  ^;«.,  we  must  test  again 
with  perhaps  Jaeger's  No.  /,  or  with  "  diamond  type,"  such  as  is 
seen  on  the  second-hand  of  watches.  If  we  find  that  such  fine  type 
cannot  be  read  at  15  cfft.  we  conclude  that  the  near  point  lies 
somewhere  beyond  the  1 5  cm. 

The  principal  point  lies  close  to  the  plane  which  passes  through 
the  sclero-corneal  border.  We  can  therefore  measure  the  distance 
from  the  corneal  margin  when  the  eye  is  looking  straight  ahead, 
and  call  it  the  distance  of  the  near  point. 

In  all  text-books  of  ophthalmology  and  physics  that  I  have  examined,  the  statement 
is  found  that  the  near  point  is  at  "  some  distance  in  front  of  the  eye."  This  is  too  in- 
definite. Donders^  measured  to  the  near  point  from  the  anterior  nodal  point.  I  consider 
this  incorrect,  for  ray  analyses  on  //.  2/  et  seq.  have  clearly  shown  that  only  the  (ante- 
rior) principal  point  is  to  be  considered,  v.  Graefe  devised  a  special  instrument  for  the 
estimation  of  the  near  point,  the  rod-optometer.     It  consists  of  a  frame  in  which  several 


*  "  Anomalien  der  Refraktion  und  Accommodation,"  II.  Auflage,  S.  26  u.  32. 


44 


THE    FUNCTION    TESTS. 


black  wires  are  stretched  parallel  to  each  other.  On  the  frame  is  a  tape-measure  which 
can  be  wound  up  on  a  spool  by  a  spring.  The  spool  is  held  at  the  temple  of  the  eye  to 
be  examined,  and  the  frame  is  approached  to  the  eye  till  the  wires  can  no  longer  be 
distinguished  ;  then  it  is  withdrawn  to  the  point  where  they  become  clearly  visible  again, 
and  this  distance  from  the  edge  of  the  cornea  is  read  off  on  the  tape  measure.  Another 
kind  of  optometer  is  in  more  general  use  than  v.  Graefe's,  for  it  furnishes  a  short  cut  to 
the  estimation  of  the  refraction  of  the  eye  as  well  as  of  the  visual  acuity.  Most  of  these 
consist  of  a  convex  lens  of  known  strength  and  a  series  of  photographically  reduced  test- 
types.  Fig.  J I  explains  the  principle  :  S  S  is  a  convex  lens  of  lo.o  D.  Such  a  lens  has 
a  focal  distance  of -jJ^  in.,  that  is  o.i  ni.  or  lo  cm.  Suppose  at  the  point  /',  lo  cm.  from 
the  lens,  we  place  the  test-type ;  now  an  emmetropic  eye  behind  the  lens  can  see  the 
print  distinctly  without  using  accommodation.  If  the  eye  cannot  read  unless  the  type  is 
brought  nearer  to  the  lens,  then  the  eye  must  be  myopic,  and  the  myopia  must  be  the 
stronger  the  nearer  the  print  must  be  brought  to  the  lens.  Again,  if  the  type  can  be 
read  further  from  the  lens  than  at  /"  (toward  the  left  in  Fig.  ii),  the  eye  must  be  hyper- 
opic.  For  example,  an  eye  can  read  that  type  corresponding  to  his  V aX.  4  cm.  from  /'" 
(to  the  left),  that  is,  at  a  distance  of  14  cm.  from  the  lens  ;  the  image  of  the  letters  pro- 
duced by  .S"  .S'  must  be  then  jj  cm.  to  the  right  of  the  lens,  for  if  f  is  the  focal  distance 


\r 


^_J 

\ 

M 

^—-^ 

l\ 

/ 

f                      \ 

^^^^ 

— '       " 

T 

""-- — ______ 

-^^^"^^^^-^ 



{ 

^; 

"^ 

V 

\ 

\                  / 

y 

ff 

v_y 

Fig.  II. — Pkinciple  of  the  Optometer. 


of  a  lens,  a  the  distance  of  the  object,  and  i>  that  of  the  image,  by  applying  the  formula 
I 

(I) 


'  ^=  ^  -j-  '  we  have  the  following  equation  :  — 


/o  14  X 

I  I    I    14  —  10 4    / 

10         14  X  140  140        Jj 

The  distance  of  the  lens,  S  S,  from  the  principal  plane,  ////,  must  be  considered,  but 
if  we  make  this  just  10  cm.  the  problem  becomes  very  simple.  In  that  case  every  centi- 
meter that  the  type  is  moved  from  F  toward  the  right  indicates  i.o  D  of  myopia,  every 
centimeter  of  7^  toward  the  left  indicates  /.  o  D  of  hyperopia.  In  the  example  above,  for 
instance,  the  image  lies  j>5  cm.  to  the  right  of  S  S,  or  25  cm.  behind  the  i)rincipal  plane, 
H H;  consequently  the  refractive  condition  of  the  eye  r=  -—  z=  4.0  D  II,  or  with 
test-type  4  cm.  to  the  left  of  7^ refraction  equals  4.0  D  oi H. 

That  this  rule  is  universally  applicable  can  be  shown  as  follows  :  in 
(l)  b  is  the  distance  of  the  image  from  the  lens,  S  S,  and  equals 


(2) 


/;  = 


aX  10 


Moreover,  the  refraction  of  the  eye  to  be  examined,  expressed  in  Diopters  {y),  is  : — 

100 


(3) 
Therefore 


y=^^r 


i^  =r  =F   70  + 


100 

y 


RANGE    OF    ACCOMMODATION   AND    PRESBYOPIA.  45 


Consequently 

(4)'  f^<J^  =  +  ^o+^ 

a  —  lo  y 

,     ,,  « X  '"  .    too 

^   '  a  —  10  y 

(5)  y  ^  a  —  10  or  —  a  . 

The  practical  significance  of  the  range  of  accommodation  lies  in 
the  fact  that  the  range  of  accommodation  is  dependent, ^  not  upon 
the  refractive  condition  of  the  eye,  but  upon  the  age.  For  as  age 
increases,  the  range  of  accommodation  decreases,  this  decrease  in 
the  range  of  accommodation  with  increasing  age  depending  upon 
the  changes  in  the  lens  mentioned  on  /.  ^8.  These  changes  are, 
to  be  sure,  only  completed  in  advanced  life,  but  they  commence  in 
childhood.  The  contents  of  the  lens  capsule  grows  denser  and 
stiffer  and  the  result  is  that  the  lens  grows  porportionately  sluggish 
and  shows  less  tendency  to  assume  a  spherical  shape  when  the  Zone 
of  Zinn  is  relaxed  during  contraction  of  the  muscle  of  accommoda- 
tion. We  see,  consequently,  a  decrease  in  the  range  of  accommo- 
dation already  beginning  at  a  time  when  the  rest  of  the  body, 
including  also  this  muscle  of  accommodation,  has  not  yet  reached 
maturity,  not  to  mention  passing  beyond  it.  The  following  table 
shows  the  relation  of  range  of  accommodation  to  age: — 

Age  in  years.  v4  in  Diopters.        Age  in  years.  /I  in  Diopters. 

lO, 14  45.       3-5 

15, 12  50, 2.5 

20, 10         55,     . 1.75 

25, 8.5      60 I 

30, 7         65, 0.75 

35.  5-5       70, 0.25 

40, 4-5       75. o 

If  we  can  guess  at  the  range  of  accommodation  from  a  man's  age 
we  ought  conversely  to  guess  his  age  from  his  range  of  accommo- 
dation, and  this  can  be  done,  although  such  conclusions  are  not  of 
rigid  or  official  trustworthiness.  The  above  figures  are  merely 
averages  and  do  not  exclude  deviations,  either  upward  or  downward, 
in  individual  cases.  This  is  plain  when  we  study  the  not  uncom- 
mon fact  that  in  some  persons  the  range  of  accommodation  in  one 
eye  differs  from  that  in  the  other.  ^ 

1  Only  in  very  high  degrees  of  Ametropia  is  A  less  than  niight  be  expected  from  the 
patient's  age. 

2  Schmidt- Rimpler,  Arch.  f.  Ophth.,  xiv,  I,  p.  1 19. 


46  THE    FUNCTION   TESTS. 

The  decrease  in  range  of  accommodation  by  increasing  age  has, 
as  a  consequence,  a  withdrawal  of  the  near  point  from  the  eye  (the 
far  point,  too,  is  withdrawn,  but  only  in  advanced  life  and  to  a  slight 
extent).'  As  soon  as  the  near  point  reaches  a  distance  of  2^  cm.  the 
working  power  of  the  eye  begins  to  suffer;  one  holds  anything  a 
little  further  off  in  order  to  see  it  clearly,  one  prefers  to  read  books 
and  to  look  at  objects  in  a  good,  strong  light,  for  then  the  pupils 
contract  and  rays  of  dispersion  are  shut  out, — in  fact,  a  man  whose 
near  point  is  withdrawn  to  25  cm.  suffers  from  that  condition  called 
oldsightedness,  or  presbyopia. 

It  is  evident  that  presbyopia  can  begin  at  different  periods  of  life 
in  different  conditions  of  refraction.  An  emmetrope  at  about  forty- 
two  years  becomes  presbyopic ;  a  hyperope  with  2.0  D  at  thirty- 
four  years,  a  myope  with  2.0'D  not  till  fifty-four  years.  Indeed,  a 
myope  with  M  =  ^.o  D  never  becomes  presbyopic,  for  even  after 
the  loss  of  the  total  range  of  accommodation  where  the  near  and  far 
points  coincide,  he  can  yet  see  distinctly  at  2^  cm. 

The  troubles  of  oldsightedness  can  be  removed  by  extending 
their  sphere  of  accommodation. 

Take,  for  example,  an  emmetrope  of  forty-two  and  forty-three  years.  lie  can  accom- 
modate from  infinity  to  2^  cm.  (equal  to  4.0  D)  ;   at  a  distance  of  jj  cm,  he  could  see 

plainly  if  he  had  accommodative  power  of ^=  j.o  D,  this  being  i^  of  his  entire  range 

of  accommodation.  Now  an  eye  can  read  continuously  and  without  trouble  only  at  a 
distance  that  requires  at  the  most  about  %  of  its  accommodative  power.  In  the  above 
case,  therefore,  we  give  a  convex  lens  of  i.o  D.  By  the  aid  of  this,  which  brings  his  far 
point  to  —  =  100  cm. ,  added  to  his  accommodative  power  of  j.o  D,  his  near  point 
is  brought  to  — - —  =  20  cm.  ;  to  read  at  jj  cm.  demands  an  adjustment  equal  to  j.o  D, 
but  if  I.o'  D  of  this  is  supplied  by  the  lens,  the  patient  need  use  only  2.0  D  of  accommo- 
dation, that  is,  ^  of  his  range  of  accommodation. 

The  above  explanations  show  clearly  that  the  same  range  of 
accommodation  may  have  a  very  different  significance  according  as 
it  belongs  to  an  emmetropic,  a  myopic,  or  a  hyperopic  eye.  For 
example,  an  emmetrope  with  A  =  5.0  D  controls  all  space  from  in- 
finity to  =  0.2  m.  =  20  cm.  in  front  of  his  eye;  his  sphere  of 
accommodation  is  therefore  endless.  A  myope  of  il/=  ^.o  D  with 
A  =  5.0  D  controls  only  the  small  interval  from  his  far  point  at  —  in. 
to  his  near  point,    — —  m.,  that  is,  0.2^  in.  to  o.ii  in.,  or  from  2^ 

4  +  5  '  ^  u 

to  //  cm.;  his  field  is  therefore  only  i^  cm.  Finally,  a  hyperope  of 
H  =  ^.o  D  with  A  =  J.o  D  controls  all  space  from  his  far  point, 
— -  to  his  near  point,  -^— ,  that  is,  from  25  cm.  behind  his  eye  to 


ASTIGMATISM.  47 

everything  in  front  of  his  eye  within  loo  cm.  Every  hyperope  can 
therefore  accommodate  for  all  objects  between  infinity  and  loo 
cjii.;  the  field  of  his  accommodation,  like  that  of  the  emmetrope,  is 
immeasurably  large,  but  does  not  come  closer  than  loo  cm.  to  his 
eye,  and  is  consequently  defective  at  just  those  distances  for  which 
exact  adjustment  is  of  prime  importance.  Indeed,  when  a  hyperope 
is  fifty  years  old  and  has  still  an  ^  =  2.j  D  at  his  disposal,  his 
whole  range  of  accommodation  does  not  suffice  to  adjust  his  eye 
for  infinity  (parallel  rays),  to  say  nothing  of  anything  nearer  to  him. 
Such  a  condition  is  called  absolute  presbyopia. 

Many  presbyopics  do  not  even  ask  for  glasses.  Nature  helps  them  out  in  this  by 
making  the  pupil  grow  narrow  and  narrower  with  increasing  age,  a  condition  that,  in 
spite  of  falte  dioptric  adjustment,  produces  a  tolerably  sharp  vision. 

The  fact  that  the  pupils  grow  narrower  with  increasing  years  can  perhaps  be  explained 
thus:  anyone  having  a  range  of  accommodation  of  g.o  D  reads  at  jj  cm.  distance  from 
the  eye  by  using  \  of  this  range  of  accommodation,  but  with  only  ^.o  D  of  accommodation 
at  his  disposal  he  must  use  for  the  same  purpose  |  of  his  energy.  The  contraction  of  the 
pupil  which  takes  place  during  accommodation  proportions  itself  doubtless  to  the  impulse 
given  by  the  will  to  the  ciliary  muscle,  but  is  not  related  to  the  effect  of  this  impulse  on 
the  form  of  the  lens.  It  is  therefore  plain  that,  neglecting  other  conditions,  the  pupils 
will  be  the  narrower  the  smaller  the  range  of  accommodation  is. 


6.  ASTIGMATISM,  As. 

Astigmatism  indicates  that  condition  in  which  a  homocentric 
pencil  of  rays  falling  on  the  eye  will  not  form  an  image  at  all, 
neither  in  front  of,  nor  at,  nor  behind  the  retina.  There  may  be 
several  causes  for  this.  A  slight  haziness  or  any  such  unevenness 
in  the  cornea  or  lens  suffices  to  distort  rays  from  their  prescribed 
course ;  such  irregular  astigmatism,  as  it  is  called,  will  be  discussed 
later.  We  are  now  treating  of  that  condition  which  depends  on  a 
distinct  deviation  of  one  or  all  of  the  refractive  surfaces  from  the 
spherical  form,  which  is  called  regular  astigmatism.  To  get  an 
idea  of  this  deviation,  take  a  symmetrically  shaped  egg  (an  ostrich 
egg  is  a  good  one),  cut  it  through  both  lengthwise  and  sidewise ; 
the  surface  of  that  half  cut  lengthwise  is  an  ellipse,  of  that  half  cut 
sidewise  is  a  circle.  The  circumferences  of  the  ellipse  and  of  the 
circle  cross  each  other  at  two  points  ;  at  one  of  these  points  put 
one  leg  of  a  compass  and  describe  a  circle  on  the  surface  of  the 
t.^^.  The  shell  circumscribed  by  this  circle  is  only  a  small  part 
of  the  whole,  but  we  can  speak  of  its  two  principal  meridians, 
although  strictly  speaking  one  of  them  describes  an  ellipse.     Now 


48 


THE    FUNCTION    TESTS. 


notice  that  the  diameters  of  each  of  these  two  principal  meridians 
are  different ;  such  a  surface  is  therefore  called  "  meridionally  asym- 
metrical." If  we  image  that  this  meridionally  asymmetrical  piece 
of  egg-shell  is  the  refracting  surface  (the  cornea)  between  air  and 
aqueous,  such  an  eye  would  have  a  regular  astigmatism.  We  may 
further  suppose  the  above  meridian-asymmetrically  curved  cornea, 
with  its  sharper  curved  principal  meridian,  pp.  Fig.  12,  to  be  perpen- 
dicular and  the  weaker  curved  principal  meridian,  /;//,  horizontal ;  now 
let  us  determine  what  is  the  refraction  of  a  homocentric  pencil  of 
rays  in  passing  through  this  cornea.  The  object  lies  toward  the  left 
at  infinity  on  the  optical  axis  of  the  eye;  a  pencil  of  rays  parallel  to 
this  axis  falls  on  the  cornea,  phph  ;  the  rays  that  fall  on  the  hori- 
zontal meridian,  hh,  are  marked  in  red;  their  meeting  point  is  at/". 
The  rays  that  fall  on  the  sharper  curved  perpendicular  meridian,//, 


Fig.  12. — Course  op  Luminous  Rays  through  an  Astigmatic  System. 
The  images  of  the  lines  and  the  ellipses  are  for  the  sake  of  clearness  drawn  below  their  true  position. 


obviously  must  have  their  meeting  point  at  a  shorter  distance,  say 
at/'.  The  question  now  is,  what  kind  of  image  appears  if  we  col- 
lect all  the  rays  passing  through  the  cornea  on  a  screen  (the 
retina  at/"')  or  some  other  point  on  the  axis  of  the  eye  at/"  ? 
The  answer  to  this  question  can  be  found  by  mathematical  investi- 
gation, but  as  this  is  rather  complicated,  we  must  be  satisfied  with 
the  answer  alone,  convincing  ourselves  of  its  correctness  by  a 
simple  experiment  with  a  spherico-cylindrical  lens.  We  find  that 
the  rays  coming  from  the  left  in  passing  through  the  meridian- 
asymmetrical  cornea  are  so  refracted  that  there  results  a  horizontal 
line  on  a  screen  placed  at  /',  "  the  anterior  linear  focus,"  and  on  a 
screen  at/"  a  perpendicular  line,  "  the  posterior  linear  focus."  If 
the  screen  be  placed  anywhere  between  /'  and/"  there  results  a 
circle  as  at  j  or  an  ellipse  as  at  ^,  but  never  a  true  image,  and  also 


ASTIGMATISM. 


49 


the  same  thing  results  in  case  the  screen  is  in   front  of,  as  at  /,  or 
behind,  as  at  6. 

If  the  object  is  approached  with  uniform  speed  from  infinity,  the 
lines,  p'p'  and  h'Ji' ,  separate  from  each  other  toward  the  right,  at 
first  very  slowly  but  with  increasing  speed.  This  unavoidable 
separation  of  these  "  linear  foci "  from  the  retina  can,  however,  be 
compensated  for  by  accommodation,  that  is,  by  shortening  the 
focal  distance  so  that  near  objects  can  throw  their  image  lines  on 
the  retina,  or  at  least  very  close  to  it ;  this  is  also  the  case  when 
the  object  lies  not  on  the  axis,  but  reasonably  close  to  it. 

We  can  give  an  idea,  but  not  a  demonstration,  of  the  origin  of  "  linear  foci  "  in  the 
following  manner :  Imagine  the  cornea,  hphp.  Fig.  12,  cut  into  segments  by  perpendicu- 
lar planes,  all  of  which  pass  through  the  middle  point  of  the  arc,  hh.  These  segments 
are  all  perpendicular,  all  ha%'e  the  same  diameter  as  //,  and  are  placed  the  more 
obliquely  to  the  optic  axis  the  further  they  lie  away  from  //.  The  pencil  of  rays  which 
falls  upon  the  principal  meridian,  pp,  will  form  an  image  aty"'',  a  second  pencil  which  falls 
on  a  segment  of  the  cornea  lying  to  the  right  of  //  likewise  forms  an  image  at  the  same 
distance,  f,  not,  however,  in  the  plane  of  the  entering  rays  but  rather  inward  from  it ; 
the  more  inward  the  stronger  the  curvature  of  hh  is,  or,  in  other  words,  the  more 
obliquely  the  perpendicular  corneal  segment  is  to  the  entering  plane  of  the  pencil.  The 
result  is  that  near  f  is  a  series  of  images  which  lie  the  closer  to  each  other  the  less  the 
difference  in  curvature  between  pp  and  hh.  If  this  distance  is  o,  that  is,  if  the  refract- 
ing surface  is  spherical,  then  all  these  points  of  the  single  pencil  of  rays  must  unite  at/''', 
or  the  pencil  forms  an  image  ! 

A  similar  process  of  reasoning  shows  that  at  f"  there  results  a  perpendicular  linear 
focus,  only  that  here  the  focal  points  of  the  rays  entering  above  hh  form  images  below 
f",  and  those  of  the  pencil  beneath  form  images  above /"'''. 

If  we  remember  the  statement  (at  /.  //)  that  acute  vision  is 
possible  only  in  case  every  object  forms  a  geometrically  exact 
image  on  the  retina,  it  is  clear  that  an  astigmatic  eye  must  see  in- 
distinctly, no  matter  where  the  receiving  screen  (the  retina)  may  be; 
but  the  distortion  of  the  retinal  images  differs  greatly  according  to 
the  forms  of  the  object  and  according  to  the  relation  of  the  retina 
to  the  focal  area.  Let  the  luminous  object  be  a  horizontal  line  at 
infinity  and  place  the  retina  at  the  position  of  the  anterior  linear 
foci ;  in  such  a  case  the  horizontal  line  will  obviously  appear  nearly 
as  distinct  as  to  a  normal  eye.  Then  every  point  of  the  linear 
object  will  form  a  linear  image,/'/';  these  linear  images  lie  one 
over  the  other  and  produce  a  complete  image,  which,  apart  from  its 
being  somewhat  lengthened,  is  of  exactly  the  same  shape  as  in  the 
normal  eye.  If,  however,  the  object  is  a  perpendicular  line  it  will 
4 


50  THE    FUNCTION    TESTS. 

appear  of  normal  length  but  distorted  in  width  by//;  consequently 
a  square  appears  oblong  and  a  circle  an  ellipse. 

The  relation  of  the  retina  to  the  focal  interval  of  the  meridian- 
ally  asymmetrical  system  distinguishes  the  kind  of  astigmatism 
and  its  classification.  If  the  retina  is  to  the  right  of/"  {Fig.  12), 
we  have  to  do  obviously  with  an  eye  generally  myopic  in  both 
meridians  but  of  different  degree  in  each ;  such  a  condition  is 
called  "compound  myopic  astigmatism"  {astigniatisnms  myopicus 
compositiis).  If  the  retina  is  at/",  there  is  emmetropia  in  the  hori- 
zontal meridian  and  myopia  in  the  perpendicular,  simple  myopic 
astigmatism  {astigmaiismiis  myopicus  simplex).  If  the  retina  is  in 
front  of  or  at/',  we  have  in  the  first  case  compound  hyperopic 
astigmatism  {astigmatismiis  hyperopicus  compositus),  and  in  the 
second  case  simple  hyperopic  astigmatism  {astigmatismus  hyperopi- 
cus simplex).  Finally,  if  the  retina  lies  between/'  and/",  we  have 
myopia  in  one  meridian  (here  the  perpendicular)  and  hypermetro- 
pia  in  the  other  meridian  (here  the  horizontal), — a  condition  called 
mixed  astigmatism  {astigmatismus  mixtus). 

Astigmatism  can  be  diagnosticated  in  the  following  manner  :  In 
Snellen's  test-cards  there  is  one  with  groups  of  lines,  each  group 
having  three  lines  of  the  same  size  parallel  to  each  other  and  with 
the  spaces  between  of  the  same  width  as  each  line ;  at  each  group 
is  a  number  designating  the  distance  at  which  the  line  of  that  par- 
ticular thickness  ought  to  be  perceived  at  an  angle  of  j'.  For 
example,  the  thinnest  lines  are  marked  <5.j',  designating  that  a  nor- 
mal eye  ought  to  distinguish  these  lines  from  each  other  at  6.j  m., 
no  matter  whether  they  are  placed  perpendicular,  horizontal,  or 
diagonal.  With  astigmatism  it  is  otherwise  !  An  eye  suffering 
from  simple  myopic  astigmatism,  having  the  retina  at  /"  {Fig.  12), 
in  looking  at  the  card  from  6.^  m.  can  count  the  lines  distinctly 
only  when  they  are  perpendicular.  If  the  card  is  turned  go°,  bring- 
ing the  lines  horizontal,  they  appear  to  this  eye  to  run  together  as 
blurred  lines. 

If  astigmatism  is  thus  proved  to  be  present,  the  next  step  is  to 
find  the  direction  of  the  principal  meridians.  Snellen  provides  for 
this  purpose  the  card  of  rays  or  spokes,  as  in  Fig.  ij.  If  this 
card  is  approached  from  a  distance  toward  an  eye  with,  say,  com- 
pound myopic  astigmatism,  a  certain  position  will  be  reached  where 
the  posterior  linear  focus  {h'  h'  oi  Fig.  12)  which  at  first  lay  in  front 
of  the  retina  will  now  fall  on  it ;  at  this  moment  the  perpendicular 


ASTIGMATISM. 


51 


ray  appears  black  (because  clear),  but  all  the  rest  seem  gray  (be- 
cause they  are  blurred) ;  and  more  gray  and  blurred  the  nearer  the 
ray  approaches  the  horizontal.  The  ray  that  first  appears  clear  and 
sharp  indicates  the  direction  of  the  principal  meridian  of  greater 
refraction.  If  some  oblique  ray  instead  of  the  perpendicular  one 
is  the  first  to  become  clear,  it  indicates  an  exceptional  case  of  astig- 
matism where  the  principal  meridians  are  oblique. 

The  test  with  the  figure  of  rays  is  obviously  applicable  to  all 
cases  of  astigmatism,  since  each  astigmatic  eye  can  be  made 
myopic  by  holding  an  ordinary  spherical  convex  lens  in  front  of  it ; 
that  is,  a  compound  myopic  astigmatism  can  be  induced. 

Finally,  the  astigmatism  must  be  measured.  From  what  has 
been  already  said,  it  is  evident  that  the  measure  of  astigmatism 
must  be  the  difference  between  the  degrees  of  refraction  in  the 
two  principal  meridians.  If,  for  example,  one  meridian  has 
M  =^  i.o  D  and  the  other  //"  = 

7.5  D,  then  As  =  2.s  D.     The  — — 

most  direct  way  to  measure 
astigmatism  would  be  to  meas- 
ure the  refraction  of  each  meri- 
dian separately,  and  as  a  matter 
of  fact  we  can  do  this  by  means 
of  the  stenopaic  slit.  This  little 
instrument  consists  of  a  piece  of 

metal  formed  like  a  spectacle  glass,  with  a  small  slit  in  it.  If  this 
slit  is  held  in  front  of  the  eye,  all  rays  are  shut  out  except  that 
thin  pencil  entering  through  the  slit  and  through  a  segment  of  the 
cornea  corresponding  to  it.  We  estimate  by  means  of  ordinary 
spherical  lenses  the  refraction  of  one  meridian,  turn  the  slit  around 
po°,  and  repeat  in  the  same  way  the  measurement  for  the  second 
meridian  thus  exposed. 

It  is  evident  that  in  choosing  the  width  of  this  slit  we  lie  between 
Scylla  and  Charybdis  ;  if  the  slit  is  too  narrow,  say  /  mm.  or  less, 
then  too  much  light  is  shut  out  and  very  disturbing  phenomena  of 
diffraction  occur  ;  if  the  slit  is  wider,  say  2  mm.,  then  one  meridian 
is  not  altogether  isolated,  but  a  segment  is  exposed  in  which  the 
asymmetry  of  this  meridian  becomes  active  again.  We  conclude 
from  this  that  another  method  is  more  serviceable,  namely,  that 
astigmatism  is  measured  by  the  neutralizing  cylindrical  lens.  Figs.  14. 
and  75  show  these  lenses.     Imagine  the  retina  to  be  at  the  first 


Fig. 


-Snellen's  Card  for  Testing  Astig- 
matism. 


52 


THE    FUNCTION    TESTS. 


linear  focus  of  the  dioptric  system  (/'  in  Fig.  12),  and  let  it  be  de- 
sired to  form  an  image  of  the  red  rays  likewise  at/"'.  It  is  plain 
that  this  can  be  accomplished  by  placing  in  front  of  the  cornea  a 
convex  cylindrical  lens  with  its  axis  perpendicular,  because  lumi- 
nous horizontal  rays  (from  right  to  left)  in  passing  through  such  a 
lens  are  refracted  toward  the  axis,  while  those  from  above  down- 
ward (perpendicular)  are  not  refracted ;  and  in  case  the  lens  has  a 
focal  distance  of  ^r  (where  —  =  -77- ^77),  all  rays  will  consequently 

X  J  J 

be  united  at  f.  The  rule,  therefore,  for  estimating  astigmatism  by 
means  of  neutralizing  cylindrical  lenses  runs  as  follows  :  After  deter- 
mining the  presence  of  astigmatism  and  the  position  of  the  princi- 
pal meridians  in  the  manner  above  mentioned,  and  after  determining 
by  a  preceding  test  ^  whether  myopia  or  hypermetropia  is  present, 
try  on  a  myopic  eye  a  concave  cylinder  with  axis  perpendicular 
to  the  meridian  of  greater  curvature;  the  cylinder  with  which  the 


Fig.  14. — A  Convex 
Cylinder. 


Fig.  15. — A  Concave 
Cylinder. 


best  V  is  contained  measures  the  degree  of  myopic  astigmatism 
present.  Try  on  a  hypermetropic  eye  a  convex  cylinder  with  axis 
perpendicular  to  the  meridian  of  lesser  curvature ;  the  cylinder 
with  which  the  best  V\%  obtained  measures  the  degree  of  hyper- 
opic  astigmatism  present.  If  there  is  mixed  astigmatism,  concave 
and  convex  cylinders  must  be  tried  with  axes  as  above,  till  the  best 
Fis  obtained. 

Such  examinations  require  patience  and  a  grasp  of  the  theory  of 
the  subject  on  the  physician's  part.  In  many  cases,  especially  of 
hyperopic  astigmatism,  a  good  result  cannot  be  obtained  without 
atropin  or  homatropin,  since  every  effort  of  accommodation,  though 
it  may  not  change  the  astigmatism  itself,  must  alter  the  relation 
of  the  image  to  the  retina ;  a  given  lens  will  therefore  seem  to 
effect  a  good  result  at  one  moment  and  a  bad  result  at  another. 


1  Generally  we  use  for  preliminary  tests   as  to  the  nature   of  a  case  the  objective 
methods  of  examination  described  on  /.  97. 


LIGHT   SENSE. 


53 


II.  LIGHT  SENSE. 

By  light  sense  we  mean  that  ability  of  the  eye  to  distinguish 
different  intensities  of  light,  and  it  is  therefore  the  essence  of  all 
vision,  since  even  the  letters  and  figures  of  a  Snellen's  test-card 
are  obviously  recognized  by  the  difference  between  the  black  of 
the  letters  and  the  white  of  the  background.  Consequently  the 
acuteness  of  vision  of  an  eye  cannot  be  estimated  without  call- 
ing the  light  sense  into  play.  The  converse,  however,  is  possible, 
for  we  can  estimate  the  light  sense  without  reference  to  the  acute- 
ness of  vision.  Since  Fechner's  time  a  distinction  is  customarily 
made  between  the  sense  of  stimulatio7i  and  the  sense  of  contrast. 
The  sense  of  stimulation  expresses  the  power  to  distinguish  the 
effect  produced  by  the  smallest  possible  quantity  of  light  when  all 
else  is  absolutely  dark.  The  sense  of  contrast  expresses  the  power 
to  distinguish  the  effect  produced  by  the  smallest  possible  differ- 
ence in  intensities  between  two  unequally  illuminated  objects. 
This  has  been  called  a  superfluous  refinement,  as  the  ability  to 
distinguish  a  shade  of  light  from  absolute  darkness  is  only  a  step 
in  the  functional  distinction  of  more  from  less  light ;  but  it  is 
worthy  of  consideration  that  to  a  certain  extent  there  is  an  influ- 
ence of  one  illuminated  area  of  the  retina  upon  another,  and  it  is 
therefore  a  different  matter  whether  I  compare  the  illumination  of 
two  objects  or  whether  I  distinguish  one  single  bright  spot  in  an 
otherwise  absolutely  dark  space. 

Moreover,  it  is  maintained  (though  disputed  by  some)  that  in 
certain  diseases  absolute  and  relative  functional  activities  are  modi- 
fied quite  independent  of  each  other,  but  the  most  convincing  argu- 
ment against  any  essential  unity  between  them  lies  in  the  fact  that 
the  sense  of  stimulation  becomes  greater  with  a  decrease  in  the 
illumination. 

The  sense  of  stimulation  can  be  tested  by  Foerster's  photometer. 
This  consists  of  a  box  \  m.  long,  \  m.  broad,  and  \  m.  high, 
painted  black  on  the  inside.  On  one  side  are  two  peek  holes,  a  a, 
for  the  eyes  to  be  tested,  with  a  curtain,^  b,  to  shut  off  either  eye  at 
will.  Next  to  these  holes  is  a  window,  c,  covered  with  oiled  paper 
and  so  arranged  by  movable  shutters,  </<^,  that  by  turning  the  screw, 
e,  a  square  hole  of  any  desired  size  is  adjusted  at  the  window.  The 
size  of  this  hole  can  be  read  off  on  the  scale,/,  which  is  connected 
rigidly  to  the  upper  shutter  and  slides  on  a  standard  below.     The 


54 


THE    FUNCTION    TESTS. 


little  window,  c,  admits  light  from  a  candle  placed  in  a  separate  com- 
partment, g,  so  that  no  light  is  thrown  directly  upon  the  eye  under 
examination.  On  the  wall  opposite  the  peek  holes  there  are  black 
marks,  hhh,  on  a  white  ground.  The  test  consists  in  determining 
that  size  of  window  at  which  the  black  marks  on  the  white  ground 
become  noticeable.  The  size  of  the  window  is  the  measure  of  the 
amount  of  light  entering  the  box,  and  this  amount  of  light  that 
makes  the  marks  visible  measures  the  sense  of  stimulation  of  the 
retina.  For  example,  if  one  eye  can  see  the  black  marks  when  the 
size  of  the  window  is  2  sq.  mm.,  while  another  does  not  see  them  till 
the  window  is  20  sq.  mm.,  the  functional  activity  of  this  last  eye  is 


Fig.  16. — Fokrster's  Photometer. 
Represented  here  with  the  doors  open.     When  in  use  both  doors  are  closed. 

ten  times  greater,  its  light  sense  ten  times  smaller  than  that  of  the 
first  eye. 

In  experimenting  with  this  instrument  it  will  soon  be  noticed 
that  the  retinal  activity  in  the  same  eye  is  distinctly  affected  by  the 
conditions  of  illumination  under  which  it  was  placed  immediately 
before  the  trial.  If  a  patient  is  led  from  daylight  into  the  dark 
room  where  the  instrument  is,  and  tested  at  once,  the  size  of  the 
window  {c)  must  be  quite  large  in  order  to  make  the  marks  visible, 
but  at  every  repetition  of  the  test  the  opening  will  be  smaller,  until 
finally,  after  something  like  half  an  hour,  each  test  will  give  approx- 
imately the  same  result.     We  conclude  from  this  that  with  the 


LIGHT   SENSE.  55 

exclusion  of  all  extraneous  light  a  change  takes  place  in  the  eye, 
consisting  of  an  increase  in  the  sensitiveness  to  light  (measured  as 
above).  This  change  in  the  eye  implies  an  adaptation  to  extrane- 
ous illumination,  or  the  lack  of  it.  In  passing  from  light  to  dark- 
ness this  adaptation  takes  place  at  first  very  quickly,  but  soon  be- 
comes slower,  though  an  essential  equilibrium  is  never  obtained 
even  after  prolonged  seclusion  in  darkness.  The  same  conclusion 
is  reached  from  the  circumstance  that  even  in  complete  darkness  we 
are  conscious  of  continually  changing  subjective  light  phenomena. 

This  act  of  adaptation  every  one  has  doubtless  observed  in  his  own  case.  In  going 
some  summer's  day  from  the  brightness  of  sunlight  into  a  dark  room  protected  by  cur- 
tains and  blinds,  one  can  at  first  see  nothing  at  all  ;  but  objects  in  the  room  soon  become 
visible,  and  after  a  quarter  of  an  hour  one  can  see  in  the  dim  light  as  well  as  in  the  day- 
light before.  We  have  only  presumptions  of  what  this  adaptation  depends  on.  One 
circumstance,  though  probably  not  the  essential  one,  is  the  play  of  the  pupil  that  widens 
in  the  dark,  and  to  that  extent  admits  more  light  into  the  eye  from  any  illuminated  object. 
It  is  probable  that  the  essential  factor  in  the  process  of  adaptation  is  to  be  found  in  the 
retina  ;  we  can  imagine  on  the  one  hand  a  movement  of  the  pigment  of  the  epithelial 
cells  (external  retinal  layer,  Fig.  no),  and,  on  the  other,  a  new  formation  and  collection 
of  visual  purple  in  the  outer  elements  of  the  rods. 

The  sense  of  contrast  of  an  eye  can  be  measured  by  Masson's 
disk.  This  instrument  is  constructed  as  follows  :  A  black  disk  and 
a  white  one  of  equal  size  have  in  the  center  a  hole  through  which 
passes  an  axle.  Both  disks  have  a  slit  from  the  center  to  the  cir- 
cumference, and  the  disks  are  movable,  so  "as  to  admit  of  forming 
with  the  uncovered  parts  a  black  and  white  disk  which  can  be  ad- 
justed to  give  any  required  proportion  of  black  or  white.  If  now  the 
axle  is  revolved  with  the  two  disks,  the  resulting  effect  is  no  longer 
black  and  white,  but  gray,  and  becomes  grayer  in  proportion  as 
white  preponderates  over  black,  or  vice  versa.  If  a  third  and  smaller 
black  disk  is  now  fastened  upon  the  axle,  when  this  is  revolved 
we  see  an  interior  black  disk  surrounded  by  a  gray  edge.  The  rela- 
tive functional  activity  for  light  perception,  that  is,  the  sensitiveness 
of  the  retina  to  contrast,  can  be  measured  by  the  amount  of  white 
in  the  large  white  disk,  which  can  be  left  uncovered  by  the  large 
black  disk  before  the  gray  edge  around  the  central  black  disk  ceases 
to  be  distinguishable. 

Besides  Masson's  disks  and  Foerster's  photometer,  there  are 
other  methods  for  testing  the  light  sense,  by  which  the  acuteness  of 
vision  is  estimated  at  the  same  time.  A  mere  mention  of  the 
principle  must  suffice. 


56  THE    FUNCTION    TESTS. 

In  the  ordinary  Snellen's  test-cards  the  black  letters  are  about 
sixty  times  less  bright  than  the  white  background.^  Now,  this  re- 
lationship can  be  changed  by  using,  instead  of  black  letters,  gray 
letters  of  different  shades  on  either  white  or  black  ground.  The 
less  the  difference  required  between  the  brightness  of  the  letters 
and  that  of  the  background,  to  make  the  letters  discernible  to  the 
eye,  the  greater  is  the  sensitiveness  of  the  retina. 

Finally,  the  method  may  be  tried  of  testing  by  Snellen's  cards  in 
reduced  light,  either  in  a  darkened  room  or  by  placing  smoked 
glasses  before  the  eye  to  be  tested. 

In  these  experiments  three  functions  come  into  play — 

(i)    Vision. 

(2)  Light-sense. 

(3)  Adaptation. 

At  the  first  glance  this  might  seem  inappropriate,  but  these  dif- 
ferent functional  tests  admit  of  determining  one  condition,  or  at 
least  of  investigating  its  degree,  that  is,  the  condition  oi  hemeralopia 
or  night-blindness.  This  is  present  when  sight  is  relatively  worse 
in  diminished  light  than  would  be  the  case  in  a  healthy  eye  with 
the  same  illumination.  Hemeralopics  are  therefore  about  as  help- 
less as  the  blind  in  the  evening  twilight  or  in  the  light  of  street 
lamps,  although  in  good  daylight  they  may  have  normal  vision. 
Hemeralopia  was  formerly  called  a  reduction  in  the  sense  of  light 
with  slow  adaptation,  bilt  recently  Kuschbert,  and  especially  Treitel, 
have  declared  that  it  depends  particularly  upon  diminished  adapta- 
tion or  a  total  absence  of  that  function.  Supposing  that  this  view 
is  correct,  the  hemeralopic  must  have  in  good  daylight  equally  as 
good  contrast  sense  of  the  retina  as  the  healthy  eye  has,  that  is,  he 
must  be  able  to  distinguish  as  different  in  brightness  two  objects 
which  differ  only  y^^  in  their  objective  illumination  ;  this  does  not 
seem,  by  any  means,  to  be  always  the  case. 

The  demonstration  of  hemeralopia  is  often  unnecessary,  since  the 
patient  probably  comes  to  the  physician  complaining  of  night- 
blindness. 


^  According  to  photometric  comparisons  between  black  and  white  papers  made  by 
Aubert. 


COLOR-SENSE.  57 

III.  COLOR-SENSE. 

Color-sense  is  taken  to  mean  that  ability  of  the  visual  apparatus 
to  respond  with  sensations  of  special  and  individual  character  to 
stimulation  by  light  of  various  wave-lengths.  Light  rays  with 
wave-length  .ooo6g  mm.  give  the  sensation  of  red ;  rays  of 
.ooojg  give  the  sensation  of  violet ;  rays  of  wave-lengths  between 
these  give  sensations  of  yellow,  green,  blue,  etc.  We  make  the 
most  extensive  use  of  this  power  of  our  eye.  Not  only  does  the 
artist  who  revels  in  the  glorious  coloring  of  a  good  painting,  or 
the  lover  of  nature  who  delights  in  a  fair  landscape  or  a  gay  flower 
garden,  use  their  color-sense  for  enjoyment,  but  others  also  employ 
it  in  soberer  professional  duties.  Mosaic  workers,  weavers,  deco- 
rators, railway  and  marine  employees  can  hardly  carry  on  their 
vocations  without  the  ability  to  distinguish  colors.  We  can  com- 
prehend, therefore,  why  the  ophthalmologist  is  often  asked  whether 
or  not  the  color-sense  is  normal. 

One  might  suppose  that  the  answer  to  this  question  needed  no 
physician's  help,  but  that  it  would  suffice  to  lay  before  the  patient 
any  colored  objects,  like  bits  of  paper,  and  to  have  him  select  the 
colors  by  name.  This  is  a  great  error.  Indeed,  it  is  often  very 
hard  to  detect  this  failure  in  color-sense — to  demonstrate  color-blind- 
ness or  a  diminished  color-sense,  color-amblyopia.  The  color-blind 
have  learned,  often  without  realizing  it,  to  conceal  their  shortcom- 
ings, and  by  heightened  attention  and  the  use  of  the  light-sense 
to  satisfy  all  the  demands  of  existence  with  reference  to  the  recog- 
nition and  designation  of  colored  objects.  A  man,  for  example, 
who  is  incapable  of  perceiving  red — "  red-blind  " — does  not  see  a 
beech  leaf  before  him  in  its  real  coloring,  although  when  ques- 
tioned as  to  its  color  he  may  answer  "  red-brown."  He  knows 
that  beech  leaves  are  sometimes  red,  and  recognizes  this  leaf  by  its 
lesser  brightness  quite  as  well  as  the  normal  person  perceives  the 
proper  color.  It  is  particularly  difficult  to  unmask  color-blind- 
ness or  color-dulness  when  the  patient,  through  fear  of  losing  some 
position  or  other,  calls  all  his  wit  into  play  in  order  to  stand  the 
test.  It  must  be  noted,  however,  that  the  uneducated  are  easily  led 
astray  by  embarrassment  or  perhaps  by  mere  lack  of  words,  and 
unintentionally  give  a  false  name  to  a  color.  Most  methods  of 
testing  for  color-blindness,  therefore,  avoid  mentioning  the  names 
of  colors,  but  demand  that  individual  colors  be  distinguished  from 
each  other. 


58  THE    FUNCTION    TESTS. 

A  simple  and  practical,  but  by  no  means  a  very  sensitive,  method 
is  Seebeck's^  "  tuool  test." 

It  consists  of  a  collection  of  various  colored  worsteds  about  lo 
cm.  long,  and  the  thickness  of  the  finger.  It  contains,  besides  the 
spectral  colors  of  red,  orange,  yellow,  green,  blue,  and  violet,  the 
mixed  colors,  purple,  rose,  and  gray,  and  there  are  four  or  five 
different  shades  of  each  color.  In  good  daylight  give  the  patient 
the  bright  green  worsted  in  his  hand  with  the  other  skeins  scattered 
on  a  white  or  black,  or  at  any  rate  on  a  colorless  ground,  and 
without  calling  the  colors  by  name  ask  him  to  sort  out  all  the 
colors  like  the  sample  without  reference  to  the  degrees  of  tints. 
One  with  normal  sense  disposes  of  this  problem  in  a  few  moments, 
sorting  out  all  the  greens  without  hesitation  or  delay.  But  the 
color-amblyopic  acts  quite  differently.  The  greens  of  the  collection 
that  are  the  same  as  the  sample  skein  he  matches  very  naturally, 
but  at  dark  green  he  stumbles,  calls  it  a  match,  and  puts  it  back 
again  ;  then  he  picks  out  a  gray,  and  finally  even  a  red  is  laid  inde- 
cisively by  the  green  sample.  This  settles  the  question.  In 
matching  red  and  green  and  gray  he  has  shown  himself  as  red- 
green  blind !  If,  however,  he  has  withstood  the  first  test  well,  let  him 
proceed  to  the  second  and  more  difficult  one,  in  which  he  must 
match  all  the  dark  and  light  shades  with  a  rose  skein.  Rose  is, 
like  purple,  a  mixture  of  red  and  blue.  The  red-blind  patient 
cannot  detect  reds,  and  matches  blues  with  the  sample ;  the  blue- 
blind  matches  red  with  it.  In  the  same  way  a  red-blind  patient 
matches  blues  with  violet,  the  blue-blind  matches  red  with  it. 

A  second  test,  depending  upon  the  confusion  of  colors  consists 
in  having  the  patient  read  colored  letters  on  a  background  of  equal 
brightness  in  tone  but  of  the  complementary  color,  so  that  the 
letters  must  be  distinguished  by  the  specific  color  effect,  not  by  a 
background  of  less  or  greater  brightness.  This  is  a  very  exacting 
test  to  withstand  satisfactorily.  Stilling,  who  devised  it,  was  so 
successful  with  his  pseudo-isochromatic  cards  that  even  the  normal 
eye  had  difficulty  in  deciphering  the  letters.  The  surface  of  the 
card  is  divided  into  small  squares  or  into  quadrate  fields  with 
rounded  corners  {Fig.  if).  The  color  of  most  of  the  squares  is  a 
delicate  green,  but  there  are  some  of  a  delicate  red  forming  the 
letter  E  ;  there  is  thus  a  red  E  on  a  green  background,  which  for 
one  who  is  red-green  blind  is  invisible. 

*  Often  called  Holmgren's,  but  Holmgren  first  applied  it  extensively. 


COLOR-SENSE. 


59 


A  third  method  depends  on  the  fact  that  a  gray  object  on  a  red 
ground  appears  green,  on  a  green  ground  red,  on  a  blue  ground 
yellow,  and  on  a  yellow  ground  blue — the  effect  of  contrast  giving 
it  the  complementary  color. 

This  fact  can  be  made  use  of  b\' means  of  H.  Meyer's  test,  which 
consists  in  covering  with  tissue  paper  a  piece  of  gray  paper  lying  on 


Fig.  17. — Example  of  a  Stilling  Card. 

a  colored  background.  The  "  induced  "  color  shines  through  the 
tissue  paper,  often  with  a  greater  intensity  than  that  of  the  primary 
background,  but  is  apparent  only  to  the  eye  possessing  normal  color- 
sense. 

This  method  has  been  made  use  of  by  A.  Weber,  v.  Bezold,  and 
Pfluecfer  as  a  test  for  color-blindness.     Pfluesfer's  cards  for  testing 


Fig.   iS. — Example 


Pflteger  Card. 


the  color-sense  have  gray  figures,  letters,  or  marks  on  a  colored  and 
equally  bright  ground  {Fz'i^.  iS). 

The  patient  is  to  decipher  these  through  one  or  two  slieets  ot 
tissue  paper.  The  normal  eye  sees  the  gray  figures  by  contrast  in 
the  complementary  color,  and  recognizes  them  without  difficulty. 
The  color-blind,  on  the  contrarv,  sees  nothing  at  all   of  the  letters 


60  THE    FUNCTION    TESTS. 

through  the  tissue  paper.  H.  Cohn,  who  has  had  great  experience 
in  testing  for  color-blindness,  declares  that  Pflueger's  cards  are  the 
surest  and  quickest  means  of  detecting  total  defect  or  even  dulness 
of  color-sense. 

The  three  methods  mentioned  above  are  for  the  purpose,  and 
generally  have  the  result,  of  determining  the  presence  of  color- 
blindness or  color-amblyopia.  The  ophthalmologist  needs  at  times, 
however,  a  method  for  measuring  the  color-sense  of  the  patient. 
Donders  has  suggested  such  a  method.  The  principle  of  it  lies  in  the 
fact  that  the  color  of  an  object  is  recognized  by  a  normal  eye  only 
when  this  colored  object  is  seen  at  not  too  small  an  angle.  The 
minimum  visual  angle  is  different  for  different  colors  ;  supposing 
that  colored  areas  are  placed  on  a  black  ground,  the  necessary 
visual  angle  increases  in  the  direction  of  the  spectrum,  that  is,  for 
red  it  is  the  smallest,  for  violet  the  largest.  If  one  places  on  a 
blackboard  colored  squares  or  disks  of  equal  size,  the  normal  eye 
recognizes  each  color  at  its  particular  distance,  and  a  color-ambly- 
opic  eye  recognizes  and  names  those  disks  for  whose  color  it  has  not 
a  normal  sensitiveness  only  at  shorter  distances  and  at  a  greater 
visual  angle.  Obviously,  then,  color-sense  is  the  duller  the  smaller 
the  distance  at  which  a  color  is  first  distinguished. 

Bonders  expresses  this  by  the  formula :    k  =  ~^    X   ~/^)  •"  which  k  signifies 

the  color  discriminating  power  (to  be  tested),  m  the  diameter  of  the  test  oi)ject,  d,  as  in 

the  formula'  for  V,  the  distance  of  patient  from  the  test-card ;  but  D  loses  the  significance 

d 
of  the  formula   F  =  2),  and  is  by  Donders  used  to  signify  the  distance    at    which  a 

normal  eye  with  ^  =  /  ought  to  recognize  the  color  of  an  object  of  /  sq.  nun.  surface 

area.     To  these  different  values  of  D  in  the  V  formula  and  in  the  k  formula  are  to  be 

ascribed  so  many  confusing  statements  by  authors. 

Another  difference  between  the  formulae  for  color-sense  and  for  acuteness  of  vision  is 

the  fact  that  w,  d,  and  D  are  squared  (as  above) ;  this  rests  on  the  circumstance  that  the 

essential  measure  for  color-sense  is  to  be  found  in  the  amount  of  color  reflected  sufficiently 

to  produce  a  color  sensation,  and  in  this  case  the  amount  of  color  reflected  increases  as 

the  surface  of  the  object,  therefore  as  the  square  of  the  diameter. 

Donders'  method  has  been  recently  taken  up,  developed,  and 
warmly  recommended  by  Wolfberg.  He  uses  red,  yellow,  green, 
and  blue  cloth  disks  on  a  black  ground  ;  the  smallest  red  and  yel- 
low circular  disks  have  a  diameter  of  2  nun.,  the  smallest  dark 
green  and  blue  a  diameter  of  7  mm.  There  are  other  disks  of 
18  mm.  diameter,  and  finally  squares  100  mm.  on  a  side.  The 
abbreviations  are  respectively  :  r^,  yl',  gr'^,  bF,  etc.  By  means  of  these 
colored  disks  and  a  table  worked  out  by  Wolfberg  it  is  said  to 


INDIRECT    VISION    AND    FIELD    OF    VISION.  6l 

be  possible  not  only  to  measure  in  a  very  short  time  the  color-sense 
present,  but  also  to  diagnosticate  whether  discoverable  dulness  of 
color-sense  rests  upon  errors  of  refraction,  or  upon  cloudiness  of 
refractive  media,  or  upon  diseases  of  the  nervous  apparatus.  For 
example,  an  eye  with  a  F=  —  ought  to  recognize  r"  in  j.2j  in.^ 
and  bf  in  j.j  in.,  in  case  the  imperfect  vision  depends  upon  short- 
sightedness;  an  eye  with  F=r  recognizes  r"^  and  bP  only  within 
2  in.,  when  the  imperfect  vision  depends  upon  cloudiness  of  the 
refractive  media;  and,  finally,  if  an  eye  with  V  ^=-~  does  not 
recognize  i^  and  bl'  further  than  2  in.  it  certainly  points  to  defect 
of  color-sense. 

It  is  clear  that  this  method  of  investigation  must  be  extremely 
valuable  in  cases  where  the  question  is  whether  any  other  disease 
besides  cloudiness  of  the  lens  is  present,  or  whether  the  parts  of 
the  eye  back  of  the  cloudy  lens  are  healthy  or  not.  Nevertheless, 
the  trustworthiness  of  the  whole  method  has  been  strongly  denied  by 
Herzog.  The  personal  differences  in  color-sense,  as  H.  Cohn  showed 
more  than  twelve  years  ago,  are  extraordinarily  great — always 
greater  than  the  differences  in  vision.  If,  therefore,  the  ophthal- 
mologist cannot  conclude  from  the  F=    -  that  an  eye  is  normal  in 

every  respect  (for  it  might  have  F  ^  —  with  a  weak  concave  or 
convex  lens),  then  it  is  still  less  admissible  to  conclude  that  the 
eye  is  normal  in  every  respect  even  though  r"  and  bP  can  be 
recognized  at  5.5  in.  Wolf  berg  himself  acknowledges  that  a  good 
daylight  illumination  is  indispensable  for  the  success  of  his  color 
test,  and  since  this  cannot  always  be  controlled,  the  practical  appli- 
cation of  Wolf  berg's  tests  is  essentially  restricted. 

I  do,  to  be  sure,  make  use  of  this  test  in  cataract  cases  and  in  diseases  of  the  fundus, 
but  I  confess  I  do  not  get  the  continued  good  results  that  Wolf  berg  claims. 


IV.  INDIRECT  VISION  AND  FIELD  OF  VISION. 

In  the  previous  section  the  dioptrics  of  the  eye  and  the  functions 
of  the  retina  have  been  discussed  for  direct  vision  only.  An  object 
is  seen  directly  when  it  lies  on  a  line  connecting  it  with  the  nodal 
point  and  the  macula  lutea  of  the  eye.  In  this  fourth  section  we 
must  examine  acuity  of  vision,  perception  of  light,  and  perception 
of  color  for  indirect  or  peripheral  vision. 


62  THE    FUNCTION    TESTS. 

The  difference  between  direct  and  indirect  vision  can  be  illustrated 
in  the  following  manner  :  Lay  on  a  printed  sheet  an  unprinted  sheet 
with  a  point  in  the  center  ;  look  at  this  point  and  for  an  instant  draw 
the  unprinted  sheet  away ;  if  the  sheet  is  moved  back  and  forth 
quickly  enough  there  is  no  time,  even  if  the  eye  is  moved,  to  trace 
out  the  whole  line  or  even  a  word ;  consequently  only  so  many 
letters  will  be  recognizable  as  lie  at  the  spot  of  clearest  vision. 
At  a  distance  of  about  jo  cm.  we  could  read  only  four  or  six 
letters  of  ordinary  type ;  therefore,  in  case  the  glance  is  directed  to 
the  end  of  a  long  word  the  word  itself  cannot  be  read. 

Another  experiment,  applicable  off-hand,  will  illustrate  the  importance  of  indirect 
vision.  Look  through  a  tube  of  any  kind  and  hold  the  other  eye  shut ;  direct  vision  has 
not  been  impaired,  but  at  the  same  time  one  is  nearly  in  the  condition  of  a  blind  person 
when  it  comes  to  finding  one's  way  about  the  room,  on  account  of  the  complete  absence 
of  peripheral  illumination.  Indirect  vision,  therefore,  serves  to  give  us  a  general  idea 
of  our  surroundings  and  to  call  our  attention  to  important  things  that  we  at  once  look  at 
and  then,  by  means  of  direct  vision,  observe  more  accurately. 

The  examination  of  the  visual  acuity  of  the  peripheral  parts  of  the 
retina  must,  in  any  case,  begin  by  determining  the  refractive  con- 
dition of  the  eye  with  reference  to  this  retinal  zone.  On  p.  i8  it 
has  been  explained  that  in  general  a  centered  system  of  spherical 
refracting  surfaces  produces  images  only  of  such  objects  as  lie  close 
to  the  axis  of  this  system.  What  images  result  from  objects  that 
do  not  fulfil  this  condition  ;  that  is,  that  lie  at  a  distance  from  the 
axis  ?  The  question  is  relatively  easy  to  answer  in  the  case  of  an 
aphakic  eye  when  there  is  only  one  refracting  surface.  The  answer 
is  that  a  homocentric  pencil  of  rays  falling  on  the  cornea  from  the 
side  is  refracted  astigmatically.  In  case  the  object  lies  at  infinity 
and  the  cornea  has  a  curvature  sufficiently  strong  to  make  the  eye 
emmetropic,  the  posterior  focal  point  of  a  pencil  of  rays  would  fall 
in  front  of  the  retina  and  only  extremely  indistinct  vision  would  be 
possible.  Complicated  calculations  have  shown  that  with  the  con- 
ditions that  accompany  the  really  emmetropic  eye,  that  is,  with  the 
proper  refraction  at  the  cornea  and  at  the  anterior  and  posterior 
lens  surfaces,  the  posterior  focus  will  lie  on  the  retina  ;  indeed,  tak- 
ing into  consideration  the  fact  that  the  lens  is  of  a  stratified  struc- 
ture, the  result  is  that  the  linear  foci  fall  exactly  on  the  retina ;  in 
other  words,  the  eye,  thanks  to  the  numerous  refracting  surfaces,  is 
periscopic — that  is,  sharp  retinal  images  are  produced  even  from 
objects  lying  at  one  side.     With  the  aid  of  the  ophthalmoscope  the 


INDIRECT    VISION    AND    FIELD    OF    VISION.  63 

peripheral  parts  of  the  fundus  can  likewise  be  seen  clear  and  undis- 
torted,  a  fact  that  harmonizes  with  these  theoretical  deductions. 
To  be  sure,  one  sees  quite  well  the  peripheral  parts  of  the  aphakic 
eye,  although  theoretically  this  ought  not  to  be  the  case. 

In  the  emmetropic  eye  the  periphery  of  the  retina  is  easily  exam- 
ined, and,  as  Parent  has  found,  is  somewhat  more  astigmatic  than 
the  region  of  the  macula.  Axis  myopic  eyes  may  have  some 
hypermetropia  at  the  periphery,  a  fact  easily  understood  when  we 
consider  the  smaller  transverse  diameter  of  the  longer  bulbus.  In 
hyperopic  eyes,  on  the  other  hand,  the  difference  between  the  trans- 
verse and  the  longitudinal  diameters  is  but  slight. 

The  first  requisite  of  good  vision  is  therefore  complied  with,  as 
far  as  concerns  the  periphery  of  the  retina,  but  the  acuity  becomes 
proportionally  less  as  the  edge  of  the  retina  is  approached. 

According  to  Becker,  the  retinal  image  of  any  surface  that  is  seen  at  a  visual  angle  of 
7°  covers  exactly  that  part  of  the  retina  which  has  V^  i.  From  here  toward  the  peri- 
phery the  acuity  of  the  vision  of  the  retina  decreases  in  the  following  manner : — 

i.^  °  toward  the  periphery  F=  — 

4 

2.0  °      "  "  "  V=  ^ 

J 

2.5°      "         "  "  V=~ 

These  figures  correspond  to  angles  above,  below,  to  the  right,  to  the  left  from  the  center 
of  the  retina.  Further  toward  the  periphery  F  decreases  more  rapidly  above  and  below 
than  to  the  right  and  left.     At  an  area  on  the  retina  =  45°  from  the  center  V  is  only 

100 

Earlier  investigators,  Foerster  and  Aubert,  have  also  found  a  similar  reduction  of  Fin 
the  peripheral  areas  of  the  retina. 

The  explanation  of  the  reduced  sharpness  of  vision  at  the  peri- 
phery lies  obviously  in  the  arrangement  of  the  retina,  since  a  great 
distinctness  in  seeing  side  objects  is  unnecessary  for  us.  Conse- 
quently but  little  account  need  be  taken  by  the  ophthalmologist  of 
peripheral  vision. 

It  is  remarkable  that  light  perception  in  the  retinal  periphery  is 
in  inverse  proportion  to  the  acuity  of  vision  of  the  same  parts. 
Light  sense  measured  by  its  function  of  stimulation  from  the 
macula  lutea  toward  the  edge  of  the  retina  becomes  greater  in- 
stead of  less.  We  are  convinced  of  this,  if,  in  coming  from  day- 
light into  a  dark  room,  we  look  at  a  weakly  illuminated  object,  say 
a  small  piece  of  luminous  phosphorus.  Looked  at  directly,  it  is 
invisible  ;  but  when  we  turn  partly  away  from  it,  it  springs  into  view! 


64  THE    FUNCTION    TESTS, 

This  fact  has  long  been  known  to  astronomers,  and  was  referred  to 
by  Arago.  It  was  noticed  that  certain  dim  stars,  the  moons  of 
Uranus,  for  example,  were  visible  only  when  one  directed  the  tele- 
scope to  one  side  of  them. 

This  weak  functional  activity  of  the  macula  lutea  was  explained 
as  depending  on  slow  adaptation,  but  investigation  has  shown  that 
even  after  several  hours'  rest  in  a  dark  room,  the  light  sense  of  the 
retinal  center  still  remains  the  less,  that  of  the  periphery  the 
greater.  Recently  one  investigator  (Mueller- Lyer)  has  had  the 
self-denial  to  keep  his  head  stuck  in  a  dark  box  for  eight  hours,  and 
the  reward  for  his  endurance  was  the  conviction  that  even  then  the 
retinal  periphery  remained  more  sensitive  to  light  than  the  center. 

The  fact  that  the  center  of  the  retina  is  less  sensitive  to  light 
than  its  periphery  depends  most  probably  on  the  histological 
structure  of  the  retina  itself  In  the  center  of  the  retina  there  are 
only  cones.  Now,  according  to  J.  v.  Kries,  we  have  in  the  rods 
and  cones  two  distinct  apparatuses  lying  side  by  side,  these  differ- 
ing not  only  anatomically  but  functionally.  The  rod  apparatus 
can  conduct  only  light  sensations,  but  is  so  perfectly  adapted  for 
this  purpose  that  it  responds  to  light  stimulations  which  have  no 
effect  on  the  cone  apparatus.  The  consequence  is  that  the  rod 
apparatus  plays  its  principal  part  in  weak  illumination,  and  is  there- 
fore most  completely  developed  in  animals  that  seek  their  food  at 
night,  like  the  mouse,  bats,  cats,  moles,  and  owls.  Conversely  the 
cone  apparatus  is  capable  of  responding  both  to  light  and  color 
sensations,  but  a  stronger  stimulation  is  needed  for  it ;  for  this 
reason  the  eye  perceives  the  outer  world  with  the  cone  apparatus 
when  the  illumination  is  strong,  and  it  appears  in  all  its  colors ; 
when  the  illumination  is  weak  the  world  is  perceived  with  the  rod 
apparatus  and  appears  colorless,  although  light  waves  of  various 
lengths  are  still  sent  into  the  eye. 

Quite  different  results  are  obtained,  as  Treitel  says,  if  light  perception  is  measured  in 
daylight  by  the  sense  of  contrast  in  the  retina.  There  is  in  this  case  a  steady  decline,  as 
in  visual  acuity,  in  passing  from  the  macula  lutea  toward  the  periphery.  But  the  suspi- 
cion arises  that  in  thus  measuring  light  perception  some  part  must  always  be  played  by 
visual  acuity.  Light  perception  seems  then  to  have  a  certain  dependence  on  vision, 
rising  and  falling  with  it.  The  sense  of  stimulation  of  the  retina  can  be  estimated  quite 
independently  of  vision. 

The  color  sense  decreases  with  visual  acuity  from  the  center  to 
the  periphery  of  the  retina.     This  decrease  is  so  sharp  that  the 


INDIRECT   VISION    AND    FIELD    OF   VISION.  65 

color  of  a  green  card  /  cm.  square  at  jj  cm.  distance  is  no  longer 
recognized  as  green  if  the  image  falls  30°  to  the  temporal  side  of 
the  macula  lutea.  The  statement  is,  therefore,  often  heard  that  the 
periphery  of  the  retina  is  color  blind;  the  green  blind  zone  is  the 
largest,  beginning  30°  or  20°  from  the  fovea  centralis  ;  the  red 
blind  zone  is  narrower;  while  the  smallest  and  nearest  to  the  edge 
of  the  retina  are  the  yellow  and  blue  zones.  All  this  is  true,  how- 
ever, only  when  it  is  taken  for  granted  that  the  test  object  is  of 
definite  size,  distance,  and  strength  of  light  and  color.  If  there  is 
an  increase  in  the  visual  angle  at  which  the  test  object  is  seen,  or  if 
the  strength  of  its  light  and  color  is  increased,  or  if  both  conditions 
are  present,  then  the  color-blind  zone  narrows.  Many  observers 
claim  that  the  extreme  edge  of  the  retina  is  sensitive  to  color  if 
the  stimulation  is  strong  enough  and  the  illuminated  retinal  area 
large  enough. 

For  the  ophthalmologist's  purpose  the  chief  question  concerns 
the  size,  boundaries,  and  possible  localized  defects  of  the  field  of 
vision. 

The  field  of  vision  of  an  eye  is  that  portion  of  space  from  which  an 
eye  at  rest  can  receive  impressions  of  light.  A  diagram  of  this  portion 
of  space  may  be  projected  upon  any  desired  spherical  surface 
described  about  the  nodal  point  of  the  eye.  The  extent  of  the 
field  of  vision  is  modified  on  the  one  hand  by  the  anatomical  struc- 
ture of  the  bulb,  on  the  other  hand  by  the  surroundings  of  the  eye 
itself. 

In  regard  to  the  former  point,  the  size  of  the  pupil  is  first  thought 
of.  Investigation  has  shown  that  with  a  wide  pupil  the  field  of 
vision  is  somewhat  (about  2°)  larger  than  with  a  narrow  pupil, 
other  conditions  being  equal ;  this  is  easy  to  understand.  It  is  less 
easy  to  understand  that  the  field  of  vision  becomes  larger  when  the 
surface  of  the  iris  advances,  for  instance,  during  accommodation 
for  a  near  object.  This  advance  of  the  iris  is,  however,  connected 
with  a  contraction  of  the  pupil  that  reduces  the  field  of  vision. 
Furthermore,  the  extent  of  the  retina  must  be  considered.  In 
myopia  it  happens  the  luminous  rays  entering  very  obliquely  reach 
the  fundus,  but  are  not  perceived  ;  in  this  case  the  border  of  the 
field  of  vision  would  not  be  defined  by  the  obliquity  of  the  ray  as 
it  enters  the  eye,  but  would  depend  on  how  far  the  retina  extends 
toward  the  front  of  the  bulb. 

Finally,  it  must  be  borne  in  mind  that  the  fovea  centralis  does  not 
5 


66  - —  THE    FUNCTION    TESTS. 

lie  exactly  at  the  center  of  the  retina  but  somewhat  to  the  temporal 
side  of  it.  Reckoned  from  the  fovea  centralis,  the  nasal  side  of  the 
retina  is  larger  than  the  temporal  side  ;  consequently  the  field  of 
vision  from  the  point  of  fixation  extends  more  toward  the  temporal 
side  than  it  does  toward  the  nasal  side  ;  for,  as  will  be  explained 
later  in  detail,  the  temporal  side  of  the  field  of  vision  refers  to  the 
nasal  side  of  the  retina,  and  vice  versa. 

The  eye's  surroundings  may  take  up  part  of  the  field  of  vision. 
A  prominent  nose  or  a  protruding  arch  of  the  temporal  bone  may 
usurp  the  field  of  vision  ;  indeed,  deep-set  eyes  may  be  affected  by 
the  maxillary  part  of  the  socket.  Such  modifications  may  appear 
as  limitations  when  the  field  of  vision  is  measured,  and  care  must 
therefore  be  exercised  to  avoid  confusion  on  that  score.  If  the 
glance  is  outward,  the  nose  may  have  no  influence  upon  the  field. 
A  droop  of  the  upper  lid  will  effect  a  noticeable  reduction  in  the 
extent  of  it  above. 

Measurements  of  the  field  of  vision  are  generally  made  by 
Foerster's  perimeter  ^  or  one  of  its  modifications.  Originally  this 
was  arranged  as  follows  {^Fig.  ip) :  On  a  standard  is  fixed  a  pillar, 
a,  at  whose  upper  end  the  lower  edge  of  the  orbit  is  leaned.  If  the 
right  eye  is  to  be  examined,  the  chin  is  rested  against  an  arm  at  the 
left,  d;  if  the  left  eye,  on  an  arm  at  the  right ;  this  arm  is  adjustable, 
since  the  distance  of  the  chin  from  the  eye  differs  in  different  per- 
sons. To  keep  the  eye  at  rest  the  patient  is  told  to  fix  a  point  on 
a  level  with  the  eye  fastened  at  about  J5  cm.  distance  on  another 
pillar,  c.  This  fixation  point  is  at  the  same  time  the  axis  about 
which  is  turned  the  arc  of  a  circle,  d  d,  divided  into  degrees.  This 
arc  has  a  diameter  of  about  J5  cm.,  its  middle  point  lying  above  the 
pillar,  rt,  at  the  nodal  point  of  the  eye.  If  this  arc  is  revolved  about 
the  horizontal  axis,  identical  in  this  case  with  the  visual  line  of  the 
eye,  it  describes  a  spherical  surface  about  the  nodal  point  of  the 
eye.  On  this  arc  is  adjusted  a  movable  square  disk,  white  or  col- 
ored, and  the  patient  is  requested  to  tell  without  moving  his  eye 
when  the  disk  is  visible  and  when  invisible.  This  test  is  repeated 
at  various  positions  of  the  arc,  which  can  be  read  off  on  a  scale,  s, 
at  its  axis ;  the  disk  can  in  turn  be  placed  at  every  part  of  the  field 

1  Aubert  was  the  first  to  use  an  instrument  for  measuring  the  visual  field  ;  this  was 
later  perfected  by  Foerster,  who  called  it  a  perimeter  and  introduced  it  into  ophthalmic 
practice.  Foerster's  perimeter  has  had  innumerable  modifications,  the  latest  being  the 
so-called  "  self- registering,"  which  diagrams  the  field  as  it  is  marked  out. 


INDIRECT    VISION    AND    FIELD    OF    VISION. 


67 


of  vision.  As  a  rule,  however,  it  is  sufficient  to  place  the  arc  in 
only  a  few  positions,  say  the  horizontal,  the  perpendicular,  and  four 
to  six  oblique  ones.  The  result  of  each  trial  of  a  new  position  of 
the  arc,  that  is,  the  areas  where  the  disk  is  or  is  not  visible,  is  en- 
tered on  a  diagram  such  as  is  shown  in  Fig.  20. 

This  diagram  of  the  field  of  vision  represents  the  spherical  sur- 
face described  by  the  arc  of  the  perimeter  about  the  nodal  point  of 


oooo 


Fig.  19. — Perimeter. 


the  eye.  Around  Fare  nine  circles  marked  10,  20,  jo,  to  go,  cor- 
responding to  the  parallels  of  latitude  of  a  sphere.  The  middle 
point,  F,  of  the  diagram  is  the  intersection  of  the  lines  marked  o, 
20,  4.0,  60,  80,  to  j6o,  corresponding  to  parallels  of  longitude.  By 
means  of  circles  in  the  one  case  and  the  diameters  of  circles  in  the 
other,  it  is  possible  to  register  any  point  designated  on  the  arc  of 
the  perimeter. 


68 


THE    FUNCTION   TESTS. 


In  Fig.  20  are  shown  the  outlines  of  the  normal  field  of  vision  of 
the  right  eye,  no  allowance  being  made  for  the  nose  or  upper  lid. 
As  we  see,  the  field    extends  po°  toward  the  temporal   side,   and 


^^"  160     '  i4o 

Fig.  20. — Normal  Field  of  Vision  of  the  Right  Eye  for  White  and  Three  Colors. 


only  60°  toward  the  nasal  side ;  55°  upward  and  70°  down- 
ward. By  combining  this  right  visual  field  with  a  corresponding 
left  visual  field,  we  get  such  a  result  as  is  shown  in  Fig.  21,  repre- 


FiG.  21. — Complete  Field  of  Vision  for  the  Two  Eyes 
(^Lue  is  the  field  for  the  left  eye,  ^ed  for  the  right). 


senting  the  total  field  of  vision  for  the  two  eyes.  The  Red  line 
indicates  the  field  for  the  7?ight  eye,  the  bZue  that  for  the  Zeft  eye. 
The  total  surface  circumscribed  by  the  red  and  blue  lines  is  the 


INDIRECT    VISION    AND    FIELD    OF   VISION.  69 

complete  field  of  vision  ;  but  in  each  separate  area  is  a  small  portion 
belonging  to  one  eye  alone,  the  right  portion  to  the  right  eye,  the 
left  to  the  left  eye. 

At  the  temporal  side  of  the  fixation  point  {Fig.  20),  between  10 
and  20,  a  small  circle  is  shown  in  the  diagram.  This  corresponds 
to  the  place  of  entrance  of  the  optic  nerve ;  as  it  has  no  retinal 
elements  and  as  the  nerve  fibers  alone  are  not  sensitive  to  light, 
this  appears  in  the  field  as  the  physiological  dark  spot,  scotoma, 
Mariotte's  or  the  d/ind  spot.  There  are  other  but  smaller  blind 
areas  in  the  visual  field  which  probably  correspond  to  points  of 
division  in  the  retinal  vessels. 

In  practising  measurements  of  the  field  of  vision,  one  must 
struggle  with  the  difficulty  of  overcoming  the  tendency  shown  by 
ignorant  patients  to  look  at  the  test  disk  as  soon  as  their  attention 
is  directed  to  it.  As  this  would  destroy  all  accuracy,  it  is  necessary 
to  keep  a  constant  watch  over  the  patient's  eye,  and  in  order  to  do 
this  it  is  best  to  sit  opposite  the  patient,  so  as  at  once  to  repeat  any 
measurement  in  case  the  eye  has  moved  at  all  from  the  fixation 
point. 

It  is  also  difficult  to  give  the  disk  an  equal  illumination  at  every 
position.  If  the  patient  sits  with  his  back  toward  the  window, 
sometimes  the  disk  passes  into  the  shadow  of  his  head,  and 
sometimes  the  light  from  the  window  falls  on  it,  not  directly,  but 
obliquely. 

It  must  be  further  mentioned  that  the  field  of  vision  is  rather 
larger  if  the  disk  is  moved  from  the  center  to  the  periphery  until  it 
disappears,  than  if  it  is  moved  in  the  opposite  direction.  One  eye 
must,  of  course,  be  closed  while  the  other  is  being  examined. 

By  means  of  this  method  of  examination  we  obtain  diagrams  of 
visual  field  that  are  in  some  diseases  diagnostic.  A  field  narrowed 
concentrically  is  a  sign  of  one  disease,  a  round  scotoma  of  another, 
a  segment  scotoma  of  a  third,  and  so  on,  as  will  be  illustrated 
later. 

Ordinarily,  the  field  for  white  is  taken,  but  it  is  often  of  interest 
to  discover  any  possible  defects  in  the  color  fields ;  in  doing  this 
we  use  a  red,  a  green,  a  yellow,  or  a  blue  disk  at  the  end  of  the 
arc,  and  ask  the  patient  to  tell  when  he  sees  the  color  as  it 
approaches  the  fixation  point.  The  normal  fields  for  color  are 
pfiven  in  Fi^r-  20.  This  diagram  shows  the  outlines  for  color  in 
Aubert's  right  eye,  a  soft  colored  paper  of  6^sq.  mm.  on  a  black 


70  THE    FUNCTION   TESTS. 

ground  in  the  daylight  at  20  cm.  distance  from  the  eye  being  used 
as  a  test  object.  The  color  of  larger  test  objects,  as,  for  example, 
a  red  disk  of  J2  mm.  square,  or  102^  sq.  mm.  in  area,  or  a  blue  one 
of  16  mm.  square,  or  2^6  sq.  mm.,  would  be  detected  at  the  extreme 
edge  of  the  visual  field. 

It  is  possible  to  select  shades  and  tints  of  red  and  green  disks  in  such  a  way  that  the 
red  and  green  fields  are  alike ;  the  same  is  true  for  properly  selected  blue  and  yellow 
fields. 


V.    BINOCULAR   VISION    AND    SQUINT. 
I.  PROJECTION  OF  RETINAL  IMAGES. 

Any  object  in  space  looked  at  by  a  healthy  eye  forms  a  dioptric 
image  at  the  fovea  centralis  of  each  eye.  These  images  are  per- 
ceived, but  the  cause  of  the  perception  is  to  be  ascribed  not  to  the 


a.' 

Fig.  22. — Projection  of  thb  Image  in  One  Eye. 

place  of  sensation,  the  retina,  but  to  the  outer  world,  and  the  sen- 
sation of  each  eye  is  projected  to  the  same  place ;  both  sensations 
are  fused  so  that  one  single  image  is  perceived.  This  fact  is  as 
easy,  or,  if  you  please,  as  hard,  to  explain  as  is  the  fact  that  an  ob- 
ject felt  with  two  fingers  is  perceived  as  one.  It  must  never  be 
forgotten  that  our  senses  are  but  the  raw  material  from  which,  by 
means  of  personal  and  inherited  experience,  conceptions  of  objects 
in  the  outer  world  are  formed. 

An  image  is  formed,  however,  not  only  of  the  object  looked  at, 
but  also  simultaneously  of  every  other  object  that  appears  in  the 
same  field  of  vision.  Are  the  retinal  images  of  objects  not  looked 
at  also  fused  into  one  ?  Let  us  examine  the  case  of  monocular 
vision.  The  point  looked  at,  c  {Fig.  22),  forms  its  retinal  image  at 
c',  the  points  a  and  b  their  images  at  a'  and  b'.  The  projection 
takes  place  exactly  in  the  path  of  the  rays  of  direction  ;  conse- 
quently, c'  is  projected  to  c,  a'  to  a,  and-^'  to  b,  or  in  general :  the 


PROJECTION    OF    RETINAL    IMAGES.  7 1 

projectio7t  of  monocular  vision  is  ouhvard  on  the  line  connecting  image 
and  nodal  point.  This  proposition  can  be  demonstrated  by  the  fol- 
lowing experiment :  shut  one  eye  and  place  a  prism  before  the 
other;  try  now  to  grasp  a  finger  or  any  object  placed  in  front  of 
it;  the  effort  will  always  be  made  to  one  side,  toward  the  left  if 
the  base  of  the  prism  is  toward  the  right;  too  high  if  the  base  is 
below,  and  so  forth. 

Fig.  23  explains  this  condition.  If  the  prism  were  not  introduced  into  the  path  of  the 
rays,  the  point  c  would  be  imaged  as  in  Fig.  22  at  the  fovea  centralis  at  f ;  but  in  pass- 
ing through  the  prism  the  rays  are  diverted  so  that  the  retinal  image  is  misplaced  below 
to  c' .  When  c'  is  connected  with  the  nodal  point  k,  and  this  line  is  extended  outward, 
c"  results  as  the  apparent  position  of  the  object  c.  Even  if  the  eye  behind  the  prism  is 
revolved  so  as  to  bring  the  image  c'  at  the  fovea  centralis, y,  the  same  error  would  be 
made  in  outward  projection,  for  after  the  movement  of  the  eyeball,  which  would  bring  the 
point  f  to  c" ,  where  the  position  of  the  image  of  c  is,  the  connecting  line  between  the 
fovea  centralis  and  the  nodal  point  would  still  give  the  same  result  as  in  Fig.  2j,  c'  k  c'\ 


Fig.  23. — False  Projection  through  a  Prism. 

In  the  projection  of  the  retinal  images  there  must  also  be  con- 
sidered the  impression  that  is  formed  of  the  position  of  one's  eye- 
ball, irrespective  of  the  correctness  or  falsity  of  this  impression. 
There  is  very  plain  evidence  of  this  in  some  diseases  of  the  eye 
muscles.  If,  for  example,  that  muscle  which  turns  the  right  eye 
toward  the  temple  is  paralyzed,  and  if  the  patient  attempts  to  grasp 
an  object  at  his  right  when  his  left  eye  is  closed,  he  always  goes 
to  the  side  and  to  the  right  of  it.  In  consequence  of  the  paralysis 
of  the  external  oblique  the  patient  makes  a  disproportionate  effort 
to  look  at  an  object  by  turning  the  eye  toward  the  right,  and  as  a 
result  his  estimation  falls  too  far  to  the  right  of  a  line  connecting 
the  retinal  images  and  the  nodal  point.  This  is  obviously  the  case 
not  only  for  the  point  looked  at,  but  also  for  everything  else  within 
the  visual  field.  Therefore  we  speak  of  "  false  projection  in  the 
visual  field." 

Retinal  images  are  projected  not  only  in  certain  directions  but 
also  to  definite  distances.  For  this  distance  of  the  projected  image 
there  seems  to  be  some  feelincr  of  measurement  in  that  effort  which 


72  THE    FUNXTION    TESTS. 

must  be  made  to  adjust  the  eye  for  looking  at  it  (that  is  to  say,  the 
convergence  connected  with  accommodation  in  any  eye).  How- 
ever, one  can  very  easily  convince  oneself  that  even  those  objects 
lying  beyond  the  far  point  are  estimated  at  their  proper  distance 
in  monocular  vision.  This,  of  course,  is  possible  for  us  only  in 
the  case  of  well-known  objects.  The  church  tower  at  home,  for 
example,  produces  on  the  retina  of  the  observer  an  image  that  be- 
comes greater  as  he  approaches  it.  From  the  size  of  this  retinal 
image  the  observer  estimates  very  well  the  distance  of  the  church. 
But  if  an  altogether  unknown  test  object  is  selected,  and  if  in  addi- 
tion care  is  taken  to  exclude  from  the  field  of  vision  well-known 
objects  that  might  serve  as  a  comparison,  then  estimations  of 
distances  without  the  associated  adjustment  necessary  will  be 
inexact  or  impossible. 

We  can  therefore  conclude  that  the  projection  of  the  retinal  images, 
even  of  one  eye,  is  a  very  complicated  mental  process,  in  which  the 
location  of  the  optical  images  on  the  retina,  the  subjective  concep- 
tion of  the  eye's  position  and  accommodation,  and  finally  our  know- 
ledge of  the  object  seen,  all  play  an  important  part. 

Still  more  complicated  is  the  case  in  binocular  vision.  Look  at 
a  distant  object,  say  test  letters  hanging  on  the  wall  opposite,  and 
place  a  pencil  in  the  direction  of  vision  :  the  pencil  now  appears 
double,  and  these  false  images  now  appear  in  a  false  position.  If 
one  eye  is  covered,  one  of  the  false  images  disappears  and  the  other 
apparently  jumps  into  the  correct  position.  The  above  rule  con- 
cerning projection  in  monocular  vision  is,  therefore,  not  quite 
applicable  in  binocular  vision,  since  the  left  eye  may  cause  the  right 
one  to  err,  and  ince  versa.  This  misleading  influence  of  the  covered 
eye  upon  the  uncovered  one  may  be  demonstrated  even  in  monocu- 
lar vision.^ 

The  examination  of  the  conditions  under  which,  in  binocular 
vision,  only  one  object  is  seen,  has  brought  to  light  the  following 
facts : — 

(i)  Images  of  a  particular  object  formed  on  both  foveae  centrales 
become  fused  into  only  one  visual  perception  ;  the  foveae  centrales 
are  therefore  cover  or  "  identical  points  of  the  retina." 

(2)  Any  other  object  is  seen  as  one  when  each  of  the  images  it 
forms  upon  the  retina  lies  an  equal  number  of  degrees  above,  below, 

^  Helmholtz,  "  Physiologische  Optik,"  1st  Edition,/.  6/2. 


PROJECTION    OF    RETINAL    IMAGES. 


73 


to  the  right,  or  to  the  left  of  its  fovea  centraHs.  That  point  in  the 
right  eye,  then,  which  lies  on  the  horizontal  meridian  io°  toward 
the  right,  that  is,  at  the  temporal  side  of  the  fovea  centralis,  is 
identical  with  a  retinal  point  in  the  left  eye  which  lies  io°  horizont- 
ally toward  the  right,  that  is,  at  the  nasal  side  of  its  fovea  centralis. 
The  easiest  way  to  get  an  idea  of  these  "  identical  points  "  on  the 
retina  is  to  imagine  both  eyeballs  fused  into  one,  so  that  the  fovea 
centralis  of  one  eye  and  the  perpendicular  meridian  passing  through 
it  fall  on  the  fovea  centralis  and  the  perpendicular  meridian  of  the 
other  eye,  when  all  "  identical  points  "  of  the  retinae  will  lie  together.^ 

In  some  positions  of  the 
eye  it  is  easy  to  determine 
those  points  in  space  which 
are  referred  to  the  identical 
points  of  the  two  retinae. 
When  vision  is  directed  to- 
ward infinity  all  points  in 
space  at  infinity  naturally 
become  identical,  since  rays 
ofdirectionfor  the  rightand 
left  eyes  are  parallel  and  in 
both  eyes  lead  to  points  ly- 
ing equally  distant  and  in 
the  same  direction  from  the 
fovese  centrales.  As  a  mat- 
ter of  fact,  the  distance  be- 
tween the  eyes  is  so  small 
that  anything  beyond  50  m. 
can  be  considered  as  infinity. 

In  the  case,  too,  when  the  two  eyes  look  at  a  point  lying  on  the 
same  horizontal  plane  but  at  a  finite  distance,  it  is  easy  to  determine 
the  horopter.  The  horopter  is  the  geometric  figure  drawn  tlirough 
all  points  in  space  which  are  imaged  at  identical  poi7its  on  the  retince. 
In  a  horizontal  plane  ^  the  horopter  describes  a  circle  which  is 
drawn  through  the  point  of  fixation,  F,  and  the  nodal  points  of 
both   eyes,  Ki  and  Kr,  "  Mueller's  horopter,"  Fig.  2^.     Each  point 


"■^  ft 

Fig.  24. — Mueller's  Horopter  Circle. 


^  The  geometrical  do  not  correspond  exactly  to  the  physiological  points,  but  the  differ- 
ence is  .so  slight  that  it  may  be  neglected  here. 

^  In  the  perpendicular  plane  there  is  also  a  horopter,  but  it  need  not  be  discussed  here. 


74  THE    FUNCTION    TESTS. 

on  this  circle,  a  for  example,  forms  images  ai  and   a^  at  an  equal 
number  of  degrees  distance  from  the  foveae  centrales,  fi  and  fr. 

Angle  a  Ki  F  ^=  angle  a  Kr  F 
being  angles  of  the  same  arc  a  Foi  the  circle. 
Angle  a  Ki  F^^  angle  y/  Ki  ni 
and  angle  a  Ki  F  ^=  angle /">-  Kr  ar  ; 
therefore,  angle y/  A'/  ai  =  angle  yV  Kr  Or. 

For  all  other  positions  of  the  two  eyes  the  matter  is  very  com- 
plicated and  has  no  immediate  significance  in  this  analysis. 

From  what  has  been  said  we  see  that  in  binocular  vision  some 
objects  are  perceived  singly,  others  double,  but  that  does  not  as 
yet  give  us  a  general  rule  for  binocular  projection.  The  most 
important  fact  in  this  connection  is  that  projection  is  made  as  if 
from  the  "  double  eye "  which  was  imaged  as  a  fusion  of  the 
two  eyes  into  one  {Fig.  2^).  If,  in  this  double  eye,  the  retinal 
images  of  an  object  lie  at  one  and  the  same  spot,  the  object  ap- 
pears single;  if  the  images  lie  at  different  spots,  the  object  appears 
double. 

Fig.  2j  illustrates  this.  The  red  or  right  eye  and  the  blue  or  left  eye  fix  a  point,  a, 
which  is  imaged  on  the  fovea  centralis  of  the  left  eye,y/,  and  of  the  right  eye,fr.  In 
fusing  these  eyes  into  the  red-blue  eye,  fi  and  fr  lie  together  at  fd;  a  is  seen  single 
and  projected  correctly  through  Kd  to  its  proper  location. 

Meanwhile,  a  point,  b,  within  the  horopter  circle,  a  Ki  Kr,  is  imaged  in  the  left  eye  at 
^/,  in  the  right  at  br,  and,  therefore,  further  from  its  fovea  centralis.  If  I  now  pick  up 
the  arc  fi  bi  and  carry  it  to  the  double  eye  (to  the  right  oi  fd),  and  do  likewise  with 
the  arc  fr  br,  I  obtain  in  the  double  eye  two  distinct  images  of  the  point,  b.  Projected 
through  the  nodal  point,  Kd,  they  give  the  false  images,  £r  and  B/,  lying  to  the  left  and 
right  of  the  true  object,  that  is,  crossed  or  heteronymous  ;  in  other  words,  the  false  image 
of  the  right  (red)  eye  lies  to  the  left,  and  the  false  image  of  the  left  (blue)  eye  lies  to  the 
right. 

Constructing  the  same  diagram  for  the  point,  c,  lying  without  the  horopter  circle,  we 
get  in  the  double  eye  the  separate  images,  cr  and  r/,  which  are  projected  through  the 
nodal  point,  Kd  to  y^  and  y^  The  false  image  of  the  right  eye  lies  to  the  right,  that  of 
the  left  to  the  left ;  the  images  are  on  the  same  side  of  the  eye,  homonymous. 

Applying  this  construction  {Fig.  2j)  to  ophthalmic  examination, 
there  results  the  rule  that  objects  between  the  fixatio7i  point  and  the 
observer  appear  double  and  heteronymoiis  {crossed^,  those  beyond  tlic 
fixation  point  appear  double  and  lioinonymotts  ;  or  in  other  words  : 
in  eyes  converging  more  than  is  necessary  for  monocular 
fixation  an  object  produces  double  and  homonymous  images, 
in  eyes  not  converging  enough  or  in  eyes  diverging  an  object 
produces  double  and  heteronymous  (crossed)  images. 

This  proposition  forms  the  groundwork  for  the  study  of  squint, 


PROTECTION    OF    RETINAL    IMAGES. 


/  :> 


and  must  be  for  the  ophthalmologist  as  much  a  matter  of  memory 
as  is  for  the  mathematician  his  twice  one  is  two. 

Just  one  word  more  concerning  the  fact  that  we  are  not  continu- 
ally annoyed  by  double  images  of  objects  seen  at  one  side,  a  con- 
fusion possible  from  the  above  explanation.  We  have  a  great 
abhorrence  of  double  images.     We  avoid  them  even  by  turning  the 


//•c 


Fig.  25. — Projection  op  Retinal  Images.     {A/ler  Martini.) 


eyes  into  an  uncomfortable  position.  But  this  process  is  not  ap- 
plicable to  the  double  vision  just  mentioned.  We  therefore  avoid 
double  images  by  the  simple  act  of  "  exclusion  "  of  one  or' the  other 
of  them.  This  neglect  is  a  mental  process  not  yet  quite  explained, 
the  force  of  which  can  be  appreciated  when  we  consider  that  many 
persons  are  unable  to  see  even  physiological  double  images. 


76  THE    FUNCTION    TESTS. 

2.  EYE  MOVEMENTS. 
It  has  just  been  explained  that  both  visual  h'nes  must  cross  at 
the  fixation  point  if  it  is  to  be  seen  directly  and  single.  In  order 
to  satisfy  this  condition  in  the  various  locations  and  distances  of 
any  fixation  point  the  eyes  must  be  movable.  Since  the  eye,  dis- 
regarding the  shape  of  the  cornea,  is  a  sphere,  and  since  displace- 
ments of  the  whole  sphere  are  excluded,  we  need  consider  only 
movements  of  the  sphere  about  its  middle  point.^  The  movements 
geometrically  possible  about  every  straight  line  passing  through 
the  middle  point  and  considered  as  the  axis  of  rotation,  are  only  in 
part  performed.  These  movements  are  accomplished  by  means 
of  the  four  rectus  and  the  two  oblique  muscles:  the  rectus  exter- 


-.ir£ 
Fig.  26. — The  Effect  of  the  Eve-Muscles.     (After  Hering.) 

nus,  internus,  superior,  and  inferior ;  the  obliquus  superior  and 
inferior.  The  action  of  each  muscle,  supposing  it  to  act  by  itself, 
can  be  illustrated  as  follows :  let  an  eye  look  at  a  point  exactly 
opposite  on  a  perpendicular  wall ;  if  now  one  of  the  eye  muscles 
contracts,  the  eye  is  moved  and  looks  at  another  point;  the  visual 
line  therefore  describes  on  the  wall  a  tracing  diagrammatic  of  the 
effect  of  this  muscle.  Fig.  26  shows  this  diagram  when  the  rota- 
tion point  of  the  eye  is  distant  from  the  surface  of  the  paper  the 
length  of  the  line  d  d.     The  numerals  placed  along  these  lines  indi- 


^  In  reality,  the  point  of  rotation  is  not  at  the  center  of  the  eye  but  at  a  point  lying 
l.2g  mm.  back  of  it.  This  is  true  for  the  emmetropic  eye ;  in  the  ametropic  eye  the 
condition  is  somewhat  different.  For  practical  purposes  we  may  consider  the  eye  as  a 
sphere  and  its  center  the  point  of  rotation. 


EYE    MOVEMENTS. 


// 


cate  in  degrees  the  angle  through  which  the  eye  has  moved  when 
it  looks  at  the  point  indicated  by  the  number. 

The  effect  of  the  internal  and  of  the  external  rectus  is  easy  to 
describe,  both  muscles  simply  carrying  the  visual  line  horizontally 
inward  or  outward.  It  is  more  complicated  in  the  case  of  the  four 
other  muscles.  The  line  belonging  to  the  superior  rectus  passes 
upward  and  in  a  gentle  curve  inward.  The  oblique  mark  at  the 
end  of  this  tracing  indicates  that  simultaneously  a  rotation  of  the 
eyeball  takes  place  about  the  visual  line,  "  circular  rotation,"  and 
the  position  which  the  previously  horizontal  meridian  assumes  in 
consequence  of  this  circular  rotation.  The  effect  of  the  inferior 
rectus  corresponds  to  it;  it  rotates  the  eye  strongly  downward,  a 
little  inward,  and  causes  a  circular  rotation  in  the  opposite  sense  to 
that  of  the  superior  rectus.  And,  finally,  the  oblique  muscles  :  The 
inferior  oblique  turns  the  eye  upward,  strongly  outward,  and 
rotates  it  in  a  powerful  degree  in  the  opposite  direction  to  that  of 
the  superior  rectus.  The  superior  oblique  turns  the  eye  down- 
ward and  outward  with  a  rotation  opposite  to  that  of  the  inferior 
rectus. 

In  Fig.  26  it  will  be  observed  that  an  absolute  elevation  of  the 
visual  line  is  not  effected  by  the  superior  rectus  alone.  The  in- 
ferior oblique  takes  part  in  this  result,  for  the  factors  of  movement 
outward  and  inward  are  thus  neutralized,  and  there  remains  only 
the  upward  movement  of  the  eye.  In  the  same  way  an  absolute 
depression  of  the  visual  line  is  effected  by  the  combined  action  of 
the  inferior  rectus  and  the  superior  oblique. 

The  effects  of  muscular  action  change  essentially  according  to  the  position  of  the  eye. 
In  Fig.  2j  both  eyes  are  in  the  primary  position,  that  is,  parallel,  horizontal,  and 
directed  straight  ahead.  ^ 

Suppose  the  right  eye  turned  J9°  outward  (to  the  right),  the  superior  rectus  in  this 
new  position  becomes  a  pure  elevator,  its  function  of  circular  rotation  is  lost,  and  when 
elevating  the  visual  line  from  this  new  position  the  opposing  circular  rotation  of  the  in- 
ferior oblique  is  not  compensated  for,  and  the  elevation  is  consequently  not  absolute  but 
connected  with  circular  rotation  to  the  right,  the  so-called  positive  rotation.  The  con- 
trary is  seen  if  the  right  eye  is  turned  inward  (to  the  left)  ;  now  the  circular  rotation  of 
the  superior  rectus  is  increased,  its  power  of  elevation  diminished ;  since  the  rotatory 
factor  of  the  other  elevator,  the  inferior  oblique,  is  at  the  same  time  lessened,  the  eleva- 
tion of  the  right  eye  from  this  new  position  is  connected  with  appreciable  circular  rota- 
tion to  the  left,  the  negative  rotation. 


^  The  exact  definition  of  primary  position  is  somewhat  different,  but  the  above  is 

approximately  correct  and  exact  enough  for  our  purpose. 


78 


THE    FUNCTION   TESTS. 


These  changes  in  effect,  in  consequence  of  a  changed  position,  are 
of  great  practical  importance  in  the  case  of  the  oblique  muscles  and 
the  inferior  and  superior  recti,  since  the  diagnosis  of  paralysis  of 
individual  muscles  is  often  possible  only  by  the  application  of  our 
knowledge  of  these  facts. 

In  the  previous  section  it  was  shown  that  both  eyes  act  as  a  sin- 
gle organ,  so  far  as  projection  of  retinal  images  is  concerned.  The 
same  is  true  for  eye  movements.  If  a  nervous  impulse  is  given  to 
elevate  the  left  eye,  the  same  impulse  goes  also  to  the  rectus  superior 
and  inferior  oblique  of  the  right  eye ;  or  if  an  impulse  to  the  inter- 
nal rectus  causes  the  left  eye  to  glance  to  the  right,  an  equal  impulse 


rvct.inf. 


rect.  sup. 
-rect  ext. 
rect.  int. 
odl.  sup. 


Fig.  27. — The  Eye-Musclks  prom  Above.     {According  to  Lnndolt ;  drawn  by  L.  Schroeter.) 
A  A'.  Visual  line.     D  D'.  Axisof  rotation  for  the  superior  and  the  inferior  rectus.     O  O'.  Axis  of  rotation 
for  the  oblique  muscles.     T  T'.  Axis  for  elevation  and  depression.     The  point  of  intersection  of  these 
axes  is  the  point  of  rotation  for  the  eye. 


goes  to  the  external  rectus  of  the  right  eye,  as  these  two  muscles 
effect  the  same  purpose  in  the  two  eyes.  Finally,  each  eye  must  be 
capable  of  convergence  and  divergence  to  assume  the  position  in 
Fig.  2j,  for  example.  The  two  interni  in  one  case,  the  two  externi 
in  another  case,  act  in  harmony.  Through  the  intricate  nervous 
mechanism  of  the  twelve  eye  muscles  the  eyes  are  capable  of  three 
kinds  of  movements  and  combinations  of  them  : — 

(i)  Movement  of  the  visual  line  in  a  horizontal  plane — 

rectus  internus  of  the  left  eye. 

rectus  externus  of  the  right  eye. 

rectus  externus  of  the  left  eye. 

rectus  internus  of  the  right  eye. 


{a)  to  the  right 
{b)  to  the  left 


EYE    MOVEMENTS.  79 

(2)  Elevation  and  depression  of  the  visual  line — 

(a)  elevation,  both  rectus  superior  and  obliquus  inferior  act- 
ing in  common. 

{/))  depression,  both  rectus  inferior  and  obliquus  superior  act- 
ing in  common. 

(3)  Convergence  and  divergence — 

{a)  convergence,  both  recti  interni  acting  together. 
(^)  divergence,  both  recti  externi  acting  together. 

We  make  the  most  extensive  use  of  these  eye  movements.  Any- 
thing noticed  to  the  side  of  us  at  once  arouses  our  interest ;  invol- 
untarily, often  unwillingly,  the  eye  is  turned  thither  so  as  to  bring 
the  object  opposite  the  fovea  centralis.  The  rapidity  and  exactness  of 
this  movement  is  astonishing.  As  a  rule,  the  head  is  turned  at  the 
same  time,  so  that,  as  Ritzmann  has  estimated,  a  movement  of  jo° 
toward  an  object  is  composed  of  jo°  of  eye  movement  and  20°  of 
head  movement.  The  attempt  to  look  toward  an  object  by  moving 
the  eyes  alone  can  by  many  be  accomplished  only  after  several 
unsuccessful  efforts. 

The  movements  of  convergence  and  divergence  need  particular 
mention.  They  are  inseparably  connected  with  movements  of 
accommodation.  For  example,  if  two  normal  eyes  look  at  a  point 
5^  ;«,  away,  an  effort  of  accommodation  is  made  in  both  eyes 
equivalent  to  ^.o  D,  and  such  a  convergence  of  the  eyes  takes  place 
that  the  visual  lines  cross  on  the  fixation  point,  even  if  there  is  no 
need  of  this  position,  one  eye  being  covered  or  useless,  perhaps. 

If  both  eyes  look  straight  ahead  and  then  at  a  point  /  m.  distant  on  the  plane  of  the 
eyes  and  at  the  middle  line  of  the  body,  each  of  the  two  visual  lines  describes  an  angle 
called  by  Nagel  meter-angle  (A/A),  which  is  chosen  as  the  measure  of  that  convergence 
of  the  visual  lines.  Expressed  in  degrees,  a  meter-angle  shows  a  different  value  accord- 
ing as  the  distance  of  the  eyes  from  each  other  is  greater  or  smaller.  The  distance  apart 
of  the  rotation  points  of  the  eyes  is  called  the  basal-line.  A  basal-line  of  64  mm.  gives 
to  a  MA  the  value  of  /°  £o' ;  of  5^  mm.  the  MA  is  1°  32'  45" •  The  converging  power 
of  each  eye  in  looking  at  a  point  is  inversely  proportional  to  the  distance  of  this  point. 
If  the  fixation  point  lies,  for  example,  at  ^  w.,  the  converging  power  of  the  eye  is  2 
MA  ;  if  it  lies  at  |^  /n. ,  the  converging  power  is  j  M.4,  and  so  forth. 

The  connection  between  accommodation  and  convergence,  when 
binocular  fusion  is  concerned,  is  quite  elastic.  If  an  emmetrope 
reads  fine  print  ^y^  m.  off,  each  eye  is  capable  of  accommodation 
of  4..0  D  and  a  convergence  of  ^  MA.  The  eyes  are,  however, 
capable  of  seeing  at  y^  in.  distance  with  both  convex  and  concave 
lenses,   that    is,    they    are    able    to    do    without    accommodation 


80  THE    FUNCTION   TESTS. 

(with  convex  lenses),  or  of  intensifying  it  (with  concave  lenses), 
although  convergence  of  the  visual  axes  (to  ^  MA)  remains  un- 
changed. The  interval  within  which  this  is  possible  is  called 
relative  range  of  accommodation,  that  is,  the  range  of  accommo- 
dation available  when  the  eyes  are  in  a  definite  position.  This 
relative  range  of  accommodation  owes  its  practical  importance  to 
the  fact  that  the  eyes  can,  without  discomfort,  be  adjusted  much 
longer  for  distances  at  which  the  positive  part  of  the  relative  range 
of  accommodation  is  large  in  comparison  to  the  negative  part. 
The  greatest  possible  increase  in  refractive  power  (measured  by  a 
concave  lens)  with  unchanged  convergence  is  called  the  positive 
part  of  the  relative  range  of  accommodation ;  the  amount  meas- 
ured by  a  convex  lens  is  called  the  negative  part. 

In  case  the  eyes  are  directed  to  the  far  point,  there  can  logically 
be  no  negative  part  present ;  in  case  they  converge  to  the  near 
point,  no  positive  part  is  present. 

Within  the  near  point  for  binocular  vision  accommodation  is  very  slight,  though  con- 
vergence is  still  possible,  but  the  accord  between  accommodation  and  convergence 
ceases.  Accommodation  is  still  possible,  but  it  is  effected  only  by  means  of  a  conver- 
gence to  a  point  nearer  than  that  accommodated  for.  Fig.  28  illustrates  this,  showing 
at  the  same  time  the  condition  of  relative  range  of  accommodation  in  a  normal  eye. 
The  ab.scissse  denote  degrees  of  convergence  expressed  in  meter  angles.  The  ordinates 
denote  the  power  of  accommodation  expressed  in  diopters.  The  points  of  the  diagonal, 
DD,  represent  the  different  powers  of  accommodation  normally  belonging  to  the  different 
degrees  of  convergence  given  in  the  proper  abscissae.  The  line  //''  p"  represents  the 
relative  near  points,  the  line  r  r^  r'^  the  relative  far  points.  The  distance  apart  of  any 
two  points  on  a  jserpendicular  plane  of  the  curves//''/'''  and  r  r'  r"  is  the  relative  range 
of  accommodation  for  the  degree  of  convergence  designated  by  the  abscissae ;  p'  is  the 
near  point  for  binocular  vision,/''''  the  absolute  near  point.  This  is  attained  only  with 
a  convergence  of  18  MA,  although  accommodation  amounts  to  only  10. o  D.  The  rela- 
tive range  of  accommodation  at  the  absolute  near  point  is  o. 

Of  course,  the  measure  of  the  relative  range  of  accommodation 
varies  considerably  in  different  persons  according  to  the  use  to 
which  they  put  their  eyes. 

If  accommodation  can  be  exercised  to  a  certain  degree  with  un- 
changed convergence,  then  convergence  can  logically  take  place 
without  accommodation.  The  extent  to  which  convergence  can 
be  increased  or  decreased  with  unchanged  accommodation  is  called 
the  range  of  fusion.  The  term  refers  to  the  circumstance  that 
movements  of  convergence  and  divergence  are  made  in  the  inter- 
est of  fusion,  that  is,  of  fusing  two  retinal  images  into  one  mental 
perception. 


EYE    MOVEMENTS. 


8i 


Fig.  28,  illustraling  the  relative  range  of  accommodation,  serves  also  to  illustrate  the 
range  of  fusion.  Let  us  look,  for  example,  at  the  ordinate  marked  6.0  D  and  the  line 
through  it  parallel  to  the  abscissa;  we  notice  that  this  parallel  cuts  the  near  point  curve, 
p  p'  p" ,  at/,  the  far  point  curve,  /'  r'  r" ,  at  r' .  In  other  words,  the  abscissae  belonging 
to  the  interval  /  r'  express  in  meter  angles  all  those  degrees  of  convergence  connected 
with  an  effort  at  accommodation  of  6.0  D;  the  abscissa  of  the  point  p  =  2.2  MA,  that 
of  the  point  \'  =  10  MA  ;  the  range  of  fusion  for  an  accommodation  of  6.0  D  is,  there- 
fore, 10.  —  2.2  =  7.8  MA,  the  negative  interval  being  6.0 —  2.2  =z  3.8  MA,  and  the 
positive  interval  being  10  —  6  =  4  M A. 

The  correctness  of  this  can  be  proved  by  experiment.  A  man 
with  normal  vision  can,  in  this  case,  still  accomplish  binocular 
fusion  even  if  he  looks  through  a  prism.     On  account  of  the  deflec- 


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■^ 

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Vj 

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/ 

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/ 

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Fig.  28. — Relation  Between  Accommodation  and  Convergence.     {After  Danders.) 


tion  given  to  the  rays  by  a  prism,  one  eye  must  turn  behind  the 
prism  in  order  to  image  on  its  fovea  centralis  the  object  looked  at 
by  the  other  eye.  This  turning  behind  the  prism  is  the  same  as 
an  increase  in  convergence  in  case  the  prism  is  placed  with  base 
toward  the  temple,  the  so-called  "position  of  adduction','  or  it  is 
a  decrease  of  convergence  when  the  base  is  toward  the  nose,  the 
so-called  "position  of  abduction."  The  close  connection  be- 
tween relative  range  of  accommodation  and  relative  range  of  fusion 
finds  also  a  practical  expression  in  the  fact  that  one's  eyes  can  be 
continuously  used  without  discomfort  only  for  such  distances  as 
6 


$2  THE   FUKCnON   TESTS. 

leave  quite  an  appreciable  interval  in  which  to  apply  the  relative 
range  of  fusion. 

We  can  speak  also  of  an  absolute  range  of  fusion  indicating  the 
absolute  play  of  convergence  without  reference  to  any  condition  of 
accommodation.  This,  too,  has  a  negative  and  a  positive  interval. 
The  negative  interval,  that  is,  the  possible  divergence,  is  measured 
by  the  strongest  prism  in  the  position  of  abduction  through  which 
a  person  with  normal  vision  can  still,  when  looking  at  infinity, 
accomplish  binocular  fusion ;  on  the  average  this  is  a  prism  of  j°, 
corresponding  to  a  real  divergence  of  2.j°  in  the  visual  lines.  The 
positive  part  of  the  absolute  range  of  fusion  is  decidedly  greater; 


Fic.  39 — FiBLO  fjr  Excvtt»ton.    (Aee^rtting  to  Htlmholtt.) 
( ^Lat  iot  the  Left  eye.  Xed  (or  the  ^ight  eye.) 

in  the  case  represented  in  Fi£'.  28,  for  example,  this  was  equal 
to  j8  ma  or  jj°  of  adduction  for  each  of  the  two  eyes  (when 
/  meter-angle  =  i^.$c/).  The  absolute  range  of  fusion  is  distin- 
guished from  the  absolute  range  of  accommodation  by  the  fact 
that  it  is  not  influenced  by  age. 

The  impulse  to  binocular  fusion  is  so  strong  that  even  prisms 
with  their  bases  above  or  below  can  be  overcome  through  a  com- 
pensating movement  of  the  eyes  downward  or  upward,  but  the 
fusion  interval  in  this  direction  is  a  very  restricted  one  and  has  no 
practical  significance. 

The  territory  that  we  can  cover  by  eye  movements  alone  with- 
out moving  the  head  is  called  the  field  of  excursion.     According 


STRABISMUS.  83 

to  Helmholtz,  this  excursional  field  of  the  eye  extends  upward 
and  downward  ^5°,  to  the  right  and  left  50°.  Aubert  and  Foer- 
ster  obtain  somewhat  different  results,  namely  :  upward  jo°,  down- 
ward 57°,  inward  ^°,  outward  j<?°.  The  personal  differences 
within  physiological  limits  are  obviously  considerable  and  to  a 
great  part  dependent  upon  exercise. 

Fig.  2g  gives  an  idea  of  the  extent  of  this  visual  excursion  for 
the  two  eyes,  supposing  them  to  be  at  the  distance  a  c  from  the 
surface  of  the  paper;  the  drawing  and  distance  are  therefore 
reduced  in  the  same  degree.  The  surface  bounded  by  the  blue 
line,  LL,  contains  all  points  looked  at  by  the  left  eye  ;  the  surface 
bounded  by  the  red  line,  RR,  all  points  looked  at  by  the  right  eye. 
The  area  covered  by  both  surfaces,  LL  and  RR,  represents  the 
excursion  of  binocular  vision ;  the  two  colored  surfaces  indicate 
the  lapses  caused  by  the  prominence  of  the  nose. 


3.  STRABISMUS  (Squint). 

In  normal  binocular  vision  the  visual  axes  intersect  at  the  fixa- 
tion point  It  sometimes  hc^>pens,  however,  that  only  one  eye 
fixes  while  the  visual  axis  of  the  other  misses  the  fixation  poinL 
This  condition  is  called  strabismus  (squint).  The  angle  made  by 
the  squinting  or  deflected  axis  with  the  line  it  would  assume  in 
normal  vision  is  called  the  angU  cf  squinL 

Ordinarily  the  «ag^  of  sqoint  is  described  as  dtt  a^  btlwamt  dK  ictaal  positkn  of 
the  visual  line  aad  wlnft  o^fat  to  be  the  xxxmai  fiae  an  dbac  potKalv  case.  "Bj  vsaal 
liae  is  understood  the  line  coonectiag  tiac  wdtataem  poiot,  />,  and  the  fiiarina  paMt,  f 
(^e  F  in  /%'.  jv  b  supposed  to  &e  iC  iBfiM^  to  ^^  i^^)-  ^^  visal  iae  aari  tfee 
Tisaal  axis  can,  moreover,  be  caasUeied  as  iiiriHiriT  withoat  appreeiaiile  cdbt.  Jm.  arkat 
follows>  thereliace,  we  sfaeQ  cease  to  asc  the  tena  visnal  line,  far  dbe  iii.ti.iMiiariiiii  of 
which  a  point  ia  the  outer  world  b  needed,  aad  ooafiBe  oar  aftratifi  to  the  yisoal  axb, 
whi^  can  always  be  determined  by  two  points  in  the  ere,  ^k  sodal  pocat,  IT,  mad.  the 
fawea  ceaKialb,  /' 

The  vboai  axis  is  the  phjsiokigicai  axis  of  the  eye.  It  does  not  coiacidr,  as  mi^it  be 
expected,  wt&  ^he  aaataaHcat  or  j— iiliiiai  aaas»  haft  les  anre  or  less  to «ae side  of  it. 
It  is  a  rule  that  the  phyaiakpcal  aais  cats  tihe  ceraea  at  a  poit  lyiag  to  the  aasilsadeof 
the  center  of  the  anea.  The  ■aitfr  is  sdl  Bsae  caapBcatoi  hf  the  fret  tjkat  the  sfmt- 
metrical  axb  of  the  cje  4aes  not  ejcactlycaiaode  artfhthe  j— aitiirilaxis  of  ikeeamea, 
that  ts«  with  &e  loaeest  iiiaatf-r  of  the  eameil  effipsoid.  This  kst  cots  tfe  ooaea 
somewhat  anre  to  Ae  tLayaal  side  Aaa  tte  symBaetrical  axis  of  &e  ^>e  (see  I^.  jo}. 
To  this  r.inaaa']lior.i.  is  to  be  ascribed  the  iaot  Aat  aa  aogie,  a  (ilpha)^  is  dbtiapa^ed 
froto  a«  ai^  y  (gaaiBH).     By  alpha,  a,  is  aardeatoad  the aac^betweea  the  jihgrsiakf 


84 


THE    FUNCTION    TESTS. 


ical  axis  of  the  eye  and  the  long  axis  of  the  corneal  ellipsoid.  This  definition  has  lost 
somewhat  in  market  price,  since  it  is  now  known  that  the  cornea  is  by  no  means  in  every 
case  curved  as  an  ellipsoid.  By  gamma,  j ,  is  understood  the  angle  between  the  visual 
line  and  the  symmetrical  axis  of  the  eye.  Since  the  visual  line  and  the  visual  axis  are 
parallel  to  each  other  (if  the  fixation  point  lies  at  a  distance),  and  since  the  deviation  of 
the  long  axis  of  the  corneal  ellipsoid  from  the  symmetrical  axis  of  the  eye  may  amount 
to  several  angular  minutes,  it  is  therefore  quite  permissible  for  all  practical  purposes  to 
consider  angle  a  and  angle  }  as  indentical,  that  is,  as  the  angle  between  the  phy.siological 
and  the  anatomical  axes. 

On  the  average  this  angle  amounts  to  j°,  but  can  be  larger  or  smaller,  or  even  nega- 
tive, that  is,  the  physiological  axis  may,  in  an  exceptional  case,  cut  the  cornea  at  the  tem- 
poral side  of  its  center.  In  emmetropia  angle  u  (or  angle  y)  on  the  average  ^j°,  in 
hyperopia  =  6.j°,  in  myopia  =  2°  to  2. 75°. 


'sas--?^- 


Fig.  30. 
In  order  to  give  a  better  perception,  the  angles,  a  and  y,  are  drawn  much  larger  than  is  really  necessary. 


The  task  of  the  examining  physician  is  now  a  threefold  one : — 
(i)  To  prove  the  presence  of  squint; 

(2)  To  demonstrate  on  what  the  squint  depends,  that  is,  what 
muscle  is  at  fault  and  what  is  the  diseased  condition  underlying  it ; 

(3)  To  measure  the  extent  of  the  squint  (the  angle  of  squint). 
The  first  problem  will  often  be  solved  by  the  patient  himself  or 

his  relatives,  if  the  squint  is  at  all  remarkable.  The  patient  comes 
to  the  physician  because  his  environment  seems  to  him  distorted. 
The  laity  generally  distinguish  two  kinds,  inward  and  outward 
squint,  strabismus  convergens  and  strabismus  divergens.  There  are, 
however,  numerous  cases  in  which  the  squint  is  not  demonstrable 
without  particular  investigation,  either  because  the  angle  of  squint 
is  very  small  or  because  the  squint  is  ordinarily  suppressed  for  the 
sake  of  binocular  vision.  This  last  is  called  latent  squint,  to 
distinguish  it  from  manifest  squint.  If  the  physician  wishes  to  find 
out  whether  he  has  a  case  of  squint,  he  proceeds  as  follows:  The 


STRABISMUS.  85 

physician,  standing  opposite,  holds  a  finger  in  front  of  the  patient 
and  asks  him  to  look  at  the  end  of  it.  If  the  patient  does  not 
squint,  the  visual  axes  of  both  eyes  intersect  at  the  finger  in  front 
of  him,  even  if  one  eye  is  covered,  the  nervous  association  of  ac- 
commodation and  convergence  providing  for  this  (/.  yg).  If  one 
eye  and  then  the  other  be  covered  in  turn,  no  movement  is  visi- 
ble, since  the  covered  eye  is  always  properly  adjusted.  It  is  quite 
different  in  squint.  At  the  request  to  look  at  the  finger  in  front 
of  him,  the  patient  does  so  with  only  one  eye.  If  now  the  fix- 
ing eye  is  suddenly  covered,  then  the  other — the  deviating  eye — 
makes  a  movement  in  order  to  bring  an  image  of  the  finger  on  the 
fovea  centralis.  This  movement  of  adjustment  proves  the  presence 
of  squint.  Suppose  the  patient  to  be  looking  at  the  finger  with 
both  eyes  open ;  if  the  physician  now  covers  the  left  eye  and  notices 
that  the  right  does  not  change  its  position,  he  concludes  that  the 
right  eye  was  properly  adjusted.  The  physician  now  covers  the 
right  eye  and  uncovers  the  left,  and  notices  that  the  left  eye  makes 
a  downward  movement  of  adjustment;  this  proves  that  the  left 
eye  had  deviated  upward — that  there  was  present  in  the  left  eye  an 
upward  squint  {Strabismus  sursum  vergens).  An  upward  movement 
of  adjustment  would  have  indicated  a  downward  deviation  of  the 
left  eye,  a  downward  squint  {Strabismus  deorsum  vergens). 

A  downward  movement  is,  however,  impossible  unless  the  infe- 
rior rectus  of  the  other  (the  right)  eye  contracts  at  the  same  time 
with  equal  force ;  that  is,  the  right  eye  covered  by  the  hand  turns 
downward,  and  consequently  itself  assumes  the  position  of  squint 
with  reference  to  the  finger  in  front  of  it,  the  so-called  secondary 
deviation.  If  the  left  eye  is  now  covered  and  the  right  uncovered, 
the  latter  overcomes  the  secondary  deviation  by  another  movement 
of  adjustment  upward. 

This  method  of  investigation  supposes  the  squinting  eye  to  have 
sufificient  acuity  of  vision  to  be  able  to  fix  the  finger  in  front  of  it. 
If  such  is  not  the  case,  a  small  deviation  of  the  visual  axis  is  of  no 
practical  value,  and  a  large  deviation  is  apparent  without  the  test 
just  described. 

The  second  problem,  the  investigation  of  the  muscle  at  fault,  must 
take  into  consideration  the  fact  that  squint  can  be  caused,  on  the 
one  hand,  by  a  weak  or  a  paralyzed  muscle,  and,  on  the  other  hand, 
by  an  over-powerful  muscle. 

{a)  Strabismus  paralyticus.     Let  us  consider  the  first  of  the 


86  THE    FUNCTION    TESTS. 

above  conditions.  Suppose  a  muscle,  for  example  the  internal 
rectus  of  the  left  eye,  to  be  paralyzed;  then  both  eyes  in  looking 
straight  ahead  into  space  will  probably  have  a  correct  position  ;  but 
as  soon  as  the  patient  looks  to  the  right  or  attempts  conver- 
gence, the  left  eye  remains  at  a  standstill  and  the  right  eye  alone 
obeys  the  impulse  from  the  brain  ;  there  results  an  absolute  or  a 
relative  divergence  of  the  visual  axes.  This  squint,  dependent  on 
inaction  of  a  muscle  or  group  of  muscles,  is  called  the  squint  of 
paralysis.  Strabismus  paralyticus.  From  what  is  said  above,  we 
gather  that  when  we  suspect  a  squint  from  paralysis  we  must  test 
the  extent  of  movement  in  each  eye  separately.  The  test  is  a  con- 
tinuation of  the  finger-test  just  described.  The  physician  tells  the 
patient  to  follow  the  finger  with  his  eye  when  he  moves  it 
horizontally  toward  the  right  and  left.  Under  normal  circum- 
stances the  eye  should  be  able  to  follow  the  finger  toward  the  tem- 
poral side  until  the  external  edge  of  the  cornea  reaches  the  exter- 
nal angle  of  the  palpebral  fissure,  or  toward  the  nose  until  the  inter- 
nal edge  of  the  cornea  dips  under  the  lacrimal  caruncle.  If  this 
is  not  possible,  we  assume  that  paralytic  squint  is  present,  especially 
if  the  examination  of  the  other  eye  shows  no  lack  of  muscular 
activity;  that  is,  we  can  be  sure  that  the  limited  excursion  of  the 
one  eye  is  not  merely  an  apparent  one  dependent  possibly  upon  an 
unusual  size  of  the  palpebral  fissure. 

If  one  internal  or  external  rectus  is  found  to  be  paralyzed  the 
examination  can  end  here  ;  for  to  measure  the  angle  of  squint  is  in 
this  case  of  no  service,  because  it  is  inconstant  in  paralytic  squint. 
Squint  is  not  present  at  all  in  that  territory  for  which  the  paralyzed 
muscle  is  not  called  into  play,  and  increases  in  proportion  as  the 
eye  endeavors  to  look  toward  the  side  of  the  paralyzed  muscle. 
This  is  also  true  for  the  secondary  deviation  of  the  sound  eye.  It 
is  greater  the  more  the  unsound  eye  exhausts  itself  in  the  effort  to 
fix  a  point  lying  within  the  territory  of  the  paralyzed  muscle  ;  it  is 
altogether  lacking  if  the  unsound  eye  can  fix  a  point  without  call- 
ing into  play  this  paralyzed  muscle. 

The  simplicity  of  the  demonstration  of  a  paralysis  of  a  rectus  in- 
ternus  or  externus  is  due  to  the  fact  that  a  movement  to  the  right 
and  left  is  essentially  dependent  on  these  muscles  alone.  In  eleva- 
tion or  depression  of  vision  the  relations  are  otherwise,  as  we  know. 
Since  elevation  of  the  visual  axis  is  carried  out  by  means  of  the 
superior  rectus  and  inferior  oblique,  inaction  of  one  of  these  mus- 


STRABISMUS.  8/ 

cles  renders  only  absolute  elevation  impossible.  In  case  the  superior 
rectus  of  the  left  eye  is  paralyzed  and  that  eye  tries  to  look  upward, 
it  will  appear  to  lag  behind  the  other  and  at  the  same  time  will  show 
a  noticeable  circular  rotation.  This  kind  of  circular  rotation  should 
indicate,  theoretically  at  least,  which  of  the  two  muscles  still  func- 
tionates, but  since  the  circular  rotation  is  not  pronounced,  and 
consequently  is  not  very  easy  to  detect  in  a  moving  eye,  some 
more  sensitive  test  must  be  applied  ;  fortunately,  we  have  this  in 
the  "  double  image  test."  If  the  rule  given  on/.  7^  is  inverted  and 
generalized,  we  obtain  the  following  important  deduction  that  tJie  po- 
sition of  the  two  eyes  can  be  determined  from  the  position  of  the  double 
images^  The  presence  of  homonymous  double  images  proves  that 
the  visual  axes  converge  to  a  point  lying  nearer  than  the  object 
which  appears  double  ;  and  the  presence  of  heteronymous  (crossed) 
double  images  proves  that  the  visual  axes  converge  to  a  point  lying 
beyond  the  object  which  appears  double,  this  point  being  toward 
infinity  either  in  the  positive  sense,  in  front  of  the  eye,  or  in  the 
negative  sense,  behind  it.  If  the  image  of  the  right  eye  is  lower 
than  that  of  the  left,  the  right  eye  must  be  directed  upward,  and 
so  forth.  A  circular  rotation  of  the  eye  will  be  betrayed  by  an 
oblique  position  of  one  of  the  two  double  images. 

In  this  method  of  testing  much  depends  on  bringing  a  patient  to 
a  clear  perception  of  the  double  images,  usually  an  easy  matter  in 
the  case  of  paralytic  squint.  This  form  generally  attacks  adults 
who  have  been  accustomed  for  years  to  perceive  the  retinal  images 
of  both  eyes,  and  who  are  therefore  not  able  at  once  to  neglect 
the  image  of  one  eye.  The  test  is  made  by  showing  the  patient, 
in  rather  neutral  surroundings  say,  a  dark  room,  a  bright  object 
(a  candle  is  one  of  the  best),  held  at  a  distance  of  2  or  j  m} 

To  ascertain  at  once  to  which  eye  each  image  belongs,  it  is  a 
good  plan  to  place  a  red  glass  in  front  of  the  eye  with  the  better 
vision  ;  this  eye  sees,  therefore,  a  darker  red  flame,  the  other  sees 
a  lighter  yellow  flame,  and  the  difference  in  acuteness  of  vision  is 
thus  more  easily  compensated  for. 

If  the  double  images  are  homonymous,  the  eyes  converge,  as 
has  been  said.  This  convergence  may  depend  on  paralysis  of  the 
right  externus  as  well  as  on  paralysis  of  the  left  extern  us.     Which 


^  If  the  double  images  are  very  wide  apart  it  is  of  advantage  to  bring  the  candle  to 
about  I  m.  If  they  are  near  together,  the  reverse  is  true,  and  the  test  should  be  made 
at  ^  to  6  til. 


88  THE    FUNCTION    TESTS. 

of  the  two  is  paralyzed  is  shown  when  the  candle  is  moved  hori- 
zontally from  right  to  left,  or  from  left  to  right.  If  the  candle  is 
moved  into  the  field  reached  only  by  the  paralyzed  muscle,  the 
double  images  flit  apart;  if  in  the  other  direction,  they  flit  together; 
but  if  they  remain  the  same  distance  apart,  the  squint  is  not  due  to 
paralysis. 

If  one  of  the  double  images  stands  obliquely  to  the  other  and 
perpendicular  one,  we  know — 

(1)  That  the  oblique  image  belongs  to  the  paralyzed  eye  ;  ^ 

(2)  That  a  superior  or  inferior  rectus  or  a  superior  or  inferior 
oblique  must  be  at  fault,^  for  only  these  four  muscles  are  con- 
cerned in  circular  rotation. 

There  are  other  signs  which  distinguish  a  sound  from  an  un- 
sound eye.  If  the  candle  is  moved  in  the  direction  of  the  para- 
lyzed muscle,  one  of  the  double  images  appears  to  flit  away  from 
the  other,  the  flitting  image  belonging  to  the  unsound  eye.  The 
explanation  is  plain  if  we  consider  that  when  the  candle  is  moved, 
its  image  in  the  sound  and,  as  we  assume,  fixing  eye  always  falls 
upon  the  fovea  centralis,  while  the  image  in  the  unsound  eye, 
either  totally  or  in  part  unable  to  continue  its  fixation,  passes 
across  the  retina.  This  test  can  be  a  deceptive  one,  either  because 
the  patient  does  not  observe  carefully  enough  to  tell  which  of  the 
double  images  appears  to  move,  or  because  he  is  accustomed  to 
fix  with  the  paralyzed  eye.  In  this  case  we  must  make  use  of  the 
position  of  the  double  images  to  find  out  which  eye  is  unsound, 
since  that  is  the  unsound  eye  in  which  the  image  is  nearest  to  the 
edge  of  the  visual  field, — that  is,  the  furthest  left,  if  the  left  half  of 
the  field  is  tested ;  the  furthest  upward,  if  the  glance  is  directed  up- 
ward, etc.  Let  us  take  an  example  :  Suppose  a  muscle  on  the  left 
side  is  paralyzed,  the  externus  of  the  left  eye ;  then  in  looking  to- 
ward the  left  there  must  be  convergence,  homonymous  images,  and 
the  image  of  the  left  (the  unsound)  eye  must  be  the  further  toward 
the  left.  Suppose  the  right  internus  is  paralyzed  ;  then  in  looking 
toward  the  left  there  must  be  divergence  and  heteronymous 
images ;  in  this  case  also  the  image  further  to  the  left  belongs  to 
the  unsound  eye,  this  time  the  right  one. 


'  Exceptions  are  not  unusual  and  will  be  explained  later. 

^  There  are  exceptions  here  also.  If  the  patient  looks  obliquely,  e.  g.,  upward  to  the 
right,  or  downward  to  the  left,  etc.,  there  is  a  moderate  oljliquity,  even  if  only  an  exter- 
nus or  an  internus  is  paralyzed. 


STRABISMUS.  89 

{b)  Strabismus  concomitans.  It  has  been  said  that  squint 
may  be  due  to  the  action  of  a  too  strong  or  of  a  too  weak  muscle. 
In  cases  of  this  kind  the  visual  field  of  the  squinting  eye  is  not  re- 
duced but  remains  unchanged  or  displaced.  For  example,  in 
inward  squint  due  to  a  too  strong  internus,  the  eye  cannot  be  turned 
so  far  outward  as  it  would  be  normally,  but  the  adductive  power  of 
this  eye  is  increased  by  a  certain  amount,  so  that  the  total  area 
covered  appears  about  normal  horizontally.  Squint  with  normal 
or  only  displaced  field  is  called  concomitant  or  muscular,  Strabis- 
mus concomitans. 

If  the  first  test  {p.  84)  proves  that  squint  is  present,  and  if  the 
double  image  test  (/.  88^  proves  that  it  is  not  due  to  paralysis,  we 
can  be  sure  that  the  squint  is  muscular  or  concomitant.  To 
decide  whether  this  is  manifest  or  latent  squint,  we  proceed  as  fol- 
lows:  The  patient  must  fix  the  finger  in  front  of  him;  now  cover 
one  eye.  If  the  open  eye  is  quiet  while  the  covered  eye  makes  a 
movement  that  is  corrected  as  soon  as  it  is  again  uncovered,  there 
is  obviously  a  latent  squint,  for  if  the  movement  of  correction  is 
made  by  the  covered  eye  when  the  fixation  point  remains  un- 
changed, the  conclusion  must  be  drawn  that  the  eye  squints  when 
covered,  in  order  to  restore  muscular  equilibrium  ;  when  it  is  uncov- 
ered, however,  it  returns  to  the  usual  position  for  the  sake  of  restor- 
ing single  vision  in  the  two  eyes.  It  is  worthy  of  note  that  many 
patients  of  this  class  do  not  perceive  the  double  images,  although 
they  should  appear  at  the  instant  the  movement  of  correction  is 
effected. 

Since  muscular  squint  is  treated  by  operation,  it  is  important  to 
solve  the  third  problem,  that  is,  to  measure  the  degree  of  squint. 
There  are  two  methods  used.  One  attempts  to  find  a  linear  meas- 
ure of  the  deviation  and  is  applicable  to  manifest  squint ;  the  other 
measures  by  neutralizing  prisms  and  is  preferably  applied  to  latent 
squint. 

The  linear  measure  is  taken  as  follows:  Suppose  the  case  is  of 
muscular,  manifest,  inward  squint ;  let  the  patient  fix  the  finger 
with  the  right  eye ;  while  the  fixation  is  quietly  maintained,  make 
an  ink  mark  on  the  under  lid  of  the  left  eye  exactly  below  the 
external  edge  of  the  cornea.  Now  cover  the  right  eye  ;  then  the 
left  eye,  which  has  hitherto  deviated  inward,  makes  a  movement  of 
correction  outward,  and  as  it  continues  to  look  at  the  finger,  held, 
of  course,  in  the  same  place,  make  a  second  mark  on  the  lower  lid 


90  THE    FUNCTION    TESTS. 

also  exactly  under  the  external  edge  of  the  cornea.  The  distance 
of  these  two  points  from  each  other  measures  the  amount  of  squint 
present;  we  call  a  squint,  therefore,  one  of  j  or  of  6  mm.,  etc. 
This  measurement  can  also  in  the  same  way  be  applied  to  the 
other  non-squinting  eye  ;  in  doing  this  we  measure  the  secondary 
deviation  of  the  sound  eye,  which  in  muscular  squint  is  just  as 
great  as  in  the  primary  deviation  of  the  squinting  eye. 

A  somewhat  purer  and  more  accurate  result  can  be  obtained  by 
measuring  the  squint  with  the  Laurence  strabometer.  Fig.  ji.  This 
is  held  under  the  squinting  eye,  and  the  line  in  the  millimeter  scale 
lying  exactly  below  the  external  corneal  edge  is  noticed  ;  then  the 
squinting  eye  is  made  to  fix,  thus  inducing  the  external  edge  to  lie 
above  another  line  in  the  scale  ;  the  distance  between  these  two 
lines  can  then  be  read  off  and  indicates  in  milli- 
meters the  degree  of  squint. 

A  third  method  of  measurement  is  that  of 
Hirschberg.  At  about  jj  cm.  hold  a  candle 
exactly  in  front  of  the  patient's  face,  and  while 
looking  over  the  flame  observe  its  reflections  on 
the  two  corneae.  If  the  patient  fixes  with  both 
eyes,  an  image  of  the  flame  is  seen  in  each  eye 
at  the  middle  of  the  cornea,  but  if  one  eye  devi- 
„  c  ates  inward,  the  image  in  this  eye  lies  outward 

Fig.  31.— Strabometek.  '  °  -' 

from  the  middle  of  the  cornea;  if  the  image  lies 
at  the  edge  of  the  cornea,  there  is  a  squint  of  6  mm.,  for  half  the 
width  of  the  cornea  is  just  6  mm. 

It  must  be  understood  that  all  these  methods  give  only  ajiproximate  results,  though 
they  are  sufficiently  accurate  for  all  practical  purposes.  To  obtain  greater  exactness  the 
angle  of  squint  must  itself  be  measured.  For  this  purpose  we  need  a  perimeter,  and  the 
corneal  image  of  the  candle  flame  just  mentioned.  The  squinting,  that  is,  the  left,  eye  is 
placed  at  the  middle  point  of  the  perimetric  arc,  while  the  sound  eye  looks  straight  ahead 
at  infinity.  If  no  squint  were  present,  the  left  eye  would  look  exactly  at  the  fixation 
point  on  the  perimetric  arc ;  but  if  there  is  a  squint,  we  can,  by  advancing  the  flame  along 
the  arc  until  it  is  reflected  exactly  at  the  center  of  the  cornea,  find  out  that  point  of  the 
circle  toward  which  the  eye  is  directed  on  account  of  its  squint.  The  position  of  the 
flame  is  read  off"  on  the  perimetric  arc  and  gives  immediately  the  angle  of  squint.  In  this 
method,  as  well  as  in  that  of  Hirschberg,  it  is  assumed  that  the  visual  axis  passes  exactly 
through  the  center  of  the  cornea.  This  is  not  the  case  (see  Fig.  30, p.  84).  In  both 
methods  there  is,  therefore,  a  radical  error  which  can  occasionally  exert  a  disturbing  influ- 
ence.     Measurements  made  with  the  strabometer  are  free  from  this  error. 

In  order  to  understand  the  method  of  measuring  squint  with 
neutralizing  prisms,  we  must  call  to  mind  certain  physical  facts.    In 


STRABISMUS. 


91 


a  prism  the  angle  opposite  the  base  is  called  the  refracting  angle  (« 
in  Fig.  J2).  Its  size  determines  the  amount  of  deviation  experienced 
by  luminous  rays  in  passing  through  a  prism  when  the  angle  of 
entrance  of  the  rays  and  the  refractive  index  of  the  glass  are  given. 
For  prisms  of  ordinary  glass  with  a  small  refracting  angle  («)  the 
angle  of  deviation  equals  half  the  angle  of  refraction  (/3  =  i^  a), 
assuming  that  the  rays  fall  perpendicularly  upon  the  side  of  the 
prism.  Let  us  suppose  that  the  left  eye  (Z,  Fig.  jj)  is  looking 
straight  ahead  at  a  fixation  point  at  infinity,  and  that  the  right  eye 
deviates  inward.  The  object  fixed  by  the  left  eye  will  be  imaged 
in  the  right  eye  to  the  inner  side  of  the  fovea  centralis,  f^,  say  at  a. 


Fig.  32. — Deviation  of  Luminous 
Rays  through  a  Prism. 


Fig.  33. — Neutralizing  the  Squint  by 

MEANS   OF   A    PrISM. 


and  in  the  double  eye  (Fig.  2i,  p.  75)  will  be  displaced  toward  the 
right.  If  now  a  suitable  prism  is  placed  with  the  edge  inward  in 
front  of  the  right  eye,  then  the  luminous  rays  will  be  refracted  to- 
ward the  right,  and  will  form  an  image  at  the  fovea  centralis,  f,. 
Consequently  the  eyes,  in  spite  of  the  squint,  will  see  this  distant 
object  as  a  single  image.  But,  as  can  be  seen  in  Fig.  jj,  the  most 
suitable  prism  is  the  one  in  which  the  angle  of  deviation  is  equal  to 
the  angle  a  Krfr,  obviously  the  angle  of  squint.  We  conclude,  there- 
fore, that  within  certain  limits  the  position  of  squint  is  neutralized 
by  a  prism  with  a  refracting  angle  double  the  squint  angle. 

The  measure  is  taken  as  follows:  After  the  diagnosis  has  shown 


92  THE    FUNCTION    TESTS. 

the  presence  of  a  muscular,  latent  squint,  either  upward,  down- 
ward, outward,  or  inward,  the  physician  places  in  front  of  one  of 
the  eyes  prisms  of  increasing  strength,  the  apex  toward  the  direc- 
tion of  the  deviation  {Fig.  jj).  That  prism  with  which  the  two 
eyes  obtain  normal  vision,  that  is,  the  prism  in  looking  through 
which  there  is  no  deviation  when  the  eye  is  covered  and  no  move- 
ment of  correction  when  the  eye  is  uncovered,  is  the  neutralizing 
prism,  and  as  such  is  a  measure  of  the  squint.  This  method  is 
called  A.  Graefe's  equilibrium  test. 

There  is  another  equilibrium  test  introduced  by  Graefe  the  elder,  the  v.  (iraefe's  equi- 
librium test.  It  is  made  as  follows  :  A  strong  prism  apex  upward  or  downward  is  used 
to  overcome  single  binocular  vision.  The  person  to  be  tested,  since  he  cannot  overcome 
such  a  strong  prism  in  this  position,  sees  double,  and  the  double  images  stand  one  exactly 
above  the  other,  if  muscular  equilibrium  is  maintained ;  if  it  is  not  maintained,  the  eyes 
will  now  assume  either  a  convergent  or  a  divergent  position,  since  there  is  no  necessity 
for  a  proper  convergence  to  the  fixation  point.  Consequently  the  double  images  are  seen 
displaced  not  only  perpendicularly  but  also  horizontally.  The  amount  of  horizontal  dis- 
placement can  now  be  measured  by  a  second  prism.  For  this  purpose  prisms  of  increas- 
ing strength  are  held  before  one  eye,  with  the  apex  toward  the  temple  if  the  images  are 
heteronymous  (crossed)  and  toward  the*  nose  if  homonymous,  until  the  patient  says  that 
the  images  are  again  perpendicular  one  above  the  other.  The  prism  giving  this  result 
measures  the  amount  of  horizontal  displacement. 

This  test  is  not  always  trustworthy,  because  in  many  persons  the  displacement  of  the 
false  images  in  a  deviating  eye  is  a  very  uncertain  quantity. 

[American  ophthalmologists,  led  by  Dr.  Stevens,  of  New  York, 
have  developed  and  perfected  the  old  v.  Graefe  equilibrium  test, 
not  so  much  for  the  purpose  of  detecting  latent  or  dynamic  squint, 
as  in  the  hope  of  demonstrating  some  weakness  in  muscle  balance 
which  could  cause  many  of  the  symptoms,  like  headache,  eye  strain, 
and  exhaustion,  classed  under  the  term  "  muscular  asthenopia,"  in 
contradistinction  to  the  analogous  symptoms  due  to  accommoda- 
tive asthenopia.  The  test  is  conducted  by  prisms,  the  same  prin- 
ciple applying  here  as  in  the  method  explained  above. 

The  nomenclature  also  has  been  elaborated  by  American  oph- 
thalmologists, but  is  devised  to  illustrate  the  direction  in  which 
the  visual  lines  tend,  rather  than  the  simple  effect  of  the  muscles 
themselves.  It  is  assumed  that  in  a  normal  person  the  visual  lines 
of  the  two  eyes  are  parallel,  and  that  binocular  single  vision  (fusion) 
results,  when  fixation  takes  place  for  objects  at  and  beyond  6  in. ; 
this  condition  is  called  orthophoria.  Now,  in  certain  states  of  the 
physical  system, — bad  health,  irregularity  of  the  orbit  or  of  the  in- 
sertion of  a  muscle,  or  when  there  is  a  refractive  error, — this  paral- 


STRABISMUS.  93 

lelism  may  be  lost,  and  one  visual  line  will  then  be  in  a  different 
relation  to  the  other  ;  this  general  deviation  is  called  heterophoria. 
A  tendency  of  one  visual  line  outward  is  called  exopJioria  ;  inward, 
esophoria  ;  upward,  hyperphoria.  (Hypophoria  is  not  used,  for,  al- 
though theoretically  probable,  the  alternate  position  of  the  other 
eye,  hyperphoria,  is  always  treated.)  Before  testing,  all  refractive 
errors  should  be  corrected ;  atropin  may  or  may  not  be  used. 
Elaborate  apparatus  has  been  devised  by  Stevens  and  others,  but 
the  prisms  furnished  in  a  good  case  of  lenses  suffice  for  establish- 
ing a  diagnosis. 

The  patient  is  placed  as  for  the  examination  of  the  visual  acuity, 
but  instead  of  letters  a  light  (candle)  at  6  m.  is  used,  which  is 
to  be  fixed  by  the  patient.  I  tis  best  to  place  a  red  disk  before 
the  right  eye  (unless  this  be  very  amblyopic),  since  the  contrast 
aids  the  patient  in  making  accurate  statements.  Now  place  before 
the  left  eye  a  prism  of  5°  to  70°,  base  downward.  The  eye  is 
rarely  able  to  overcome  a  vertical  prism,  and  all  effort  at  fusion 
being  thus  destroyed,  the  result  is  diplopia,  the  two  images  of  the 
candle-flame  not  lying  in  the  same  horizontal  plane  in  any  case, 
and  lying  in  the  same  vertical  plane  only  when  parallelism  of  the 
visual  lines  is  maintained — orthophoria.  The  red  image  is  correctly 
projected  and  belongs  to  the  right  eye.  Suppose  the  other  image 
lies  above  and  to  the  side  of  the  red  image.  Applying  the  rule  of 
projection  on  p.  J^,  it  is  evident  that  if  the  white  and  upper 
image  (left  eye)  lies  to  the  right  of  the  red  image  (heteronymous 
diplopia),  the  visual  lines  must  tend  away  from  each  other — exo- 
phoria — and  the  condition  is  weakness  of  adduction  in  the  interni. 
If  the  white  image  lies  to  the  left  of  the  red  image  (homonymous 
diplopia),  the  visual  lines  must  tend  toward  each  other — esophoria — 
and  the  condition  is  weakness  of  abduction  in  the  externi.  Now 
place  prisms  of  varying  strengths  in  front  of  the  right  eye,  base  in 
(abducting)  for  exophoria,  base  out  (adducting)  for  esophoria,  until 
just  that  prism  is  found  which  causes  the  two  images  to  lie  exactly 
in  the  same  vertical  plane ;  parallelism  of  the  visual  lines  is  re- 
stored, and  the  prism  effecting  this  is  said  to  measure  the  muscular 
inefficiency.' 


1  The  expression  "  to  measure  "  is  incorrect,  since  there  is  no  constant  loss  of  muscle 
efiuilibrium.  The  action  of  muscles  is  always  relative  and  inconstant,  and  the  test 
shows  only  the  tendency  of  the  equilibrium  to  be  lacking  or  excessive  by  so  many 
degrees. 


94  THE    FUNCTION    TESTS. 

The  simplest  test  for  hyperphoria  is  with  the  Maddox  rod,  which 
consists  of  a  small  glass  cylinder  in  an  opaque  disk,  made  to  fit  a 
trial  frame.  (A  very  neat  Maddox  rod  is  now  made  of  red  glass, 
the  cylindrical  portion  being  cut  out  of  the  glass;  the  disk  thus 
combines  in  one  both  red  glass  and  rod.)  This  disk  is  placed  in 
the  trial  frame,  and  if  the  rod  is  horizontal,  the  candle-flame  will 
be  changed  into  a  vertical  beam  of  light;  if  the  rod  is  vertical,  the 
beam  of  light  will  be  horizontal.  Suppose  the  rod  is  placed  verti- 
cal ;  there  are  now  two  lights,  the  beam  belonging  to  one  eye,  the 
natural  light  to  the  other.  If  the  beam  passes  directly  through  the 
center  of  the  flame  (or  if  the  flame  lies  at  the  center  of  the  beam), 
there  is  no  upward  or  downward  deviation.  If  the  two  lights  are 
not  in  the  same  horizontal  plane,  there  is  hyperphoria,  the  lower 
light  belonging,  of  course,  to  the  eye  which  has  the  greater  ten- 
dency to  deviate  upward.  By  placing  the  rod  horizontal,  the  verti- 
cal beam  may  discover  exophoria  or  esophoria,  but  the  absence  of 
signs  therefore  does  not  imply  orthophoria,  since  a  latent  tendency 
to  deviation  may  have  been  so  overcome  in  the  interest  of  fusion 
that  the  beam  passes  through  the  flame.  The  term  hypereso- 
phoria — tendency  upward  and  inward — expresses  the  condition  of 
homonymous  diplopia  with  the  two  images  in  different  horizontal 
planes.  Hyperexophoria  expresses  the  condition  of  heteronymous 
diplopia  with  the  images  in  different  horizontal  planes. 

All  these  preceding  deviations  are  assumed  to  depend  upon  lack 
of  equilibrium  between  the  recti  muscles.  A  similar  disparity  be- 
tween the  obliqui  may  be  unmasked,  as  some  ophthalmologists 
claim,  by  Savage's  test,  in  which  a  double  prism  of  several  degrees 
each  is  used,  mounted  with  bases  together,  in  a  trial-frame  disk. 
This  is  held  with  axes  vertical  before  one  eye,  while  the  other 
eye  is  covered.  The  object  of  fixation  is  a  horizontal  line  50  cm. 
The  line  is  distorted  so  as  to  appear  as  two  parallel  lines.  When 
the  other  eye  is  uncovered,  it  should  see  between  these  two  a 
third  line  parallel  to  them.  Any  loss  of  balance  between  the 
oblique  muscles  is  said  to  be  indicated  if  this  third  line  is  not 
parallel.  Suppose  the  double  prism  to  be  before  the  right  eye ; 
there  is  left  hyperphoria  if  the  middle  line  is  nearer  the  bottom ; 
there  is  exophoria  if  it  is  more  to  the  right  and  less  to  the  left ; 
there  is  esophoria  if  it  is  more  to  the  left  and  less  to  the  right. 
There  is  said  to  be  insufficiency  of  the  left  superior  oblique  if  the 
right  ends  of  the  middle  and  lower  lines  converge;  insufficiency  of 


STRABISMUS.  95 

the  left  inferior  oblique,  if  they  diverge.     By  changing  the  double 
prism  the  right  eye  may  be  similarly  tested. 

As  the  last  trial  is  conducted  at  a  distance  of  jO  cm.,  it  is  well  to 
repeat  the  preceding  prism  tests  for  equilibrium,  at  the  same  (near) 
distance,  using  instead  of  the  candle  a  small  white  cross  on  a  black 
ground.  The  results  thus  found  may  or  may  not  coincide  with 
those  found  at  6  m.  These  examinations  should  be  supplemented 
by  testing  in  each  eye  the  strength  of  the  prism  that  can  be  over- 
come by  adduction  (base  out),  and  by  abduction  (base  in),  before 
double  vision  occurs.  Muscular  power  varies,  of  course,  in  different 
eyes  and  on  different  occasions,  but  adduction  will  be  from  2j°  to 
50°  ;  abduction  from  5°  to  10°. —  H.] 


B.  OBJECTIVE  METHODS  OF  INVESTIGATION. 

I.  REFLECTION  FROM  THE  CORNEA.— 
KERATOSCOPY. 

The  surface  of  the  cornea,  being  a  separating  surface  between 
two  transparent  media,  air  and  cornea,  is  a  mirror,  and  on  account 
of  its  curve  a  convex  mirror  that  reflects  virtual  images  of  lumi- 
nous objects ;  these  images  are  upright,  diminished,  and  lie  appa- 
rently behind  the  cornea ;  they  are  commonly  but  improperly 
called  reflexes.  The  size  of  such  a  reflection  (mirror  image) 
depends  upon  the  size  of  the  object,  its  distance,  and  upon  the  cur- 
vature of  the  corneal  surface.  The  further  off  the  object  and  the 
smaller  the  radius  of  the  cornea,  the  smaller  is  the  image.  The 
shape  of  this  image  depends  upon  whether  or  not  the  corneal  sur- 
face is  spherical ;  if  it  is  so,  then  the  image  is  geometrically 
identical ;  if  the  cornea  is  astigmatic,  that  is,  asymmetrically  curved 
in  any  meridian,  the  image  is  regularly  distorted.  Finally,  the 
sharpness  and  clearness  of  the  image  is  proportional  to  the 
smoothness  of  the  cornea,  and  is  affected  by  any  depressions  or 
elevations  in  it.  In  case  there  are  any  holes,  fissures,  or  vesicles, 
the  image  is  irregularly  distorted  and  dim.  We  can,  therefore,  on 
the  one  hand,  recognize  by  means  of  these  corneal  reflections  any 
small  roughness,  excavation,  or  prominence,  and,  on  the  other, 
estimate  from  the  size,  length,  and  breadth  of  the  image  the  varia- 
tions in  radii. 

To  study  any  roughness  or  unevenness  in  the  corneal  surface, 
the  physician  turns  his  back  to  the  window  and  places  the  patient 
in  front  of  him ;  he  then  sees  the  reduced  image  of  the  window  and 
window  bars  reflected  from  the  patient's  cornea.  The  patient  is 
now  asked  to  look  at  a  finger  held  in  front  of  him  ;  by  moving  the 
finger  in  various  directions  the  eye  is  brought  into  various  posi- 
tions so  that  gradually  the  physician  has  seen  the  image  of  the 
window  reflected  from  every  portion  of  the  corneal  surface.  In 
this  way  the  whole  cornea  is  tested,  and  as  any  roughness  would 
be  apparent  to  the  finger,  in  the  same  way  an  unevenness  of  the 
corneal    surface   is   betrayed  by  an    irregularity  in   the    reflected 

96 


REFLECTION  FROM  THE  CORNEA. 


97 


image,  and  the  smallest  loss  or  unevenness  of  the  epithelium  can 
be  recognized  without  difficulty. 

The  second  step,  finding  the  corneal  curvature,  is  carried  out  by 
means  of  various  instruments  and  for  various  purposes.  In  prac- 
tice it  is  seldom  of  value  to  determine  the  actual  dimension  of  the 
radius  of  curvature ;  but,  on  the  other  hand,  it  is  doubly  important 
to  know  whether  and  in  what  degree  the  cornea  is  meridionally 
asymmetric.  For  this  purpose  the  keratoscope  was  devised,  that  of 
Wecker-Masselon  being  perhaps  the  most  used  {Fig.  j^).  It  con- 
sists of  a  blackboard  i8  cm.  square,  bordered  by  a  white  stripe 
about  i^  mm.  broad.  There  is  a  hole  in  the  center  to  look  through. 
It  is  held  by  a  handle  about  which  the  board  turns  at  its  middle 
and  in  its  own  plane,  the  amount  of  this  rotation  being  read  from 


Fig.   34. — Kkkatoscopb  of 

Wecker-Masselon. 


Fig.  35  — Scale    for    Cor- 
neal Astigmatism. 


a  scale  on  the  back  of  the  board.  The  instrument  is  held  about 
20  cm.  in  front  of  the  eye.  If  the  cornea  is  normal  the  reflected 
image  of  the  white  frame  is  a  square,  measuring  on  each  side  not 
quite  \  of  the  corneal  diameter,  but  if  the  cornea  is  meridionally 
asymmetrical  the  image  of  the  frame  loses  its  square  shape ;  if  the 
sides  of  the  square  frame  are  not  parallel  to  the  principal  meri- 
dians of  the  cornea,  the  image  is  a  rhomboid.  By  turning  the 
board  on  its  handle  the  white  frame  will  finally  take  a  position 
from  which  a  rectangular  image  is  reflected.  When  this  position 
is  found  we  have  the  direction  of  the  principal  meridians. 

The  instrument  is  handled  as  follows :  The  physician  sits  oppo- 
site the  patient  and  adjusts    the   keratoscope   so   that  the  white 
square,  illuminated  from  a  window  or  a  lamp,  is  imaged  on  the 
7 


98  OBJECTIVE    METHODS    OF    INVESTIGATION. 

cornea.  The  physician  looks  with  one  eye  through  the  hole  in 
the  keratoscope  at  the  eye  of  the  patient,  who  is  requested  to  look 
at  the  hole  from  his  side  of  the  instrument.  If  the  image  is  rectan- 
gular it  is  compared  with  a  series  of  ten  rectangles  printed  on  an 
accompanying  card  {Fig.  jj)  that  illustrates  the  corneal  images  in 
astigmatic  condition  from  o  to  lo.o  Diopters.  The  rectangle  (the 
first  one  being  a  square)  showing  the  closest  resemblance  to  the 
corneal  image  maybe  taken  as  a  measure  of  the  corneal  astigmatism 
present. 

This  Wecker-Masselon  keratoscope  can  be  had  in  a  perfected  form.  If  a  square  is 
reflected  from  an  astigmatic  cornea  as  a  rectangle,  then  there  must  be  some  rectangle 
the  image  of  which  on  this  cornea  will  appear  as  a  square.  The  square  of  the  white 
frame  may  be  changed  by  means  of  a  screw  adjustment  into  a  parallelogram.  This  screw 
is  turned  until  the  image  which  first  appears  as  a  parallelogram  is  now  reflected  as  a 
square,  the  change  effected  in  the  frame  being  the  measure  of  the  astigmatism  present. 
In  order  to  read  in  diopters  without  farther  trouble  the  astigmatism  thus  found,  the  frame 
is  arranged  with  an  empirical  scale  and  an  indicator  connected  with  the  screw. 

In  many  scientific  problems  it  is  of  interest  to  determine  the  actual  size  of  the  cornea, 
that  is,  the  radius  of  its  curvature.  This  can  be  done  by  applying  the  following  rule  :  If 
the  distance  of  an  object  from  a  convex  mirror  is  equal  to  infinity,  the  image  lies  at  the 
(virtual)  focus,  that  is,  at  one-half  the  radius  (^  r)  behind  the  reflecting  surface.  When 
the  corneal  curve  is  sharp,  objects  at  a  few  meters  distance  are  images  close  to  the  focus, 
and  the  radius  of  the  cornea  may  therefore  be  estimated  by  a  simple  proportion  : — 

If  a,  the  size  of  the  object, 

d,  its  distance  from  the  cornea,  and 
c,  the  size  of  the  image,  have  been  measured,  we  then 
have  this  ratio :       a  :  c  ^=  6  :      ;       consequently    r  =  2  -  . 

It  is  easy  to  measure  a  and  i> ;  while  c  can  be  measured  by  the  Helmholtz  or  the 
more  modern  Javal-Schiotz  ophthalmometer.  This  instrument  and  its  use  is  explained 
in  text-books  of  physiology  or  in  exhaustive  works  on  ophthalmology. 

Many  ophthalmologists  use  the  ophthalmometer  for  purely  practical  purposes,  especi- 
ally for  determining  objectively  the  presence  of  astigmatism.  I  prefer  to  use  the  Shadmu 
Test,  q.  V.  ^ 


II.  FOCAL  OR  OBLIQUE  ILLUMINATION. 

If  two  completely  transparent  media  touch  each  other,  a  reflec- 
tion of  luminous  rays  occurs  only  at  the  surface  of  separation. 
But  in  case  one  of  these  media  is  not  completely  transparent,  part 
of  the  rays  will  be  reflected  from  within  the  medium  itself,  and  the 
reflected  rays  will  therefore  be  visible.  For  that  reason  corneal  scars, 
on  account  of  their  opaqueness,  appear  as  gray  blotches.  In  many 
cases,  however,  there  is  so  little  light  reflected  that  the  lack  of 


FOCAL    OR    OBLIQUE    ILLUMINATION.  99 

transparency  cannot  be  detected  unless  special  methods  are  used. 
The  method  most  suitable  for  these  cases  is  a  strong  oblique  illumi- 
nation. By  means  of  a  lamp  and  a  convex  lens  a  very  powerful 
light  can  be  thrown  upon  the  suspected  area,  and  there  are  enough 
of  the  diffused  rays  returned  to  the  observer  to  show  him  a  gray 
spot  which  would  be  invisible  with  a  weaker  illumination.  As  the 
examination  takes  place  in  a  dark  room  no  other  light  falls  upon 
the  cornea  except  that  from  the  lamp  through  the  convex  lens  ; 
there  is,  therefore,  a  strongly  illuminated  area  on  the  cornea  sur- 
rounded by  an  area  of  weaker  illumination,  this  contrast  favoring 
the  recognition  of  any  places  from  which  the  reflection  is  weak. 
And,  finally,  one's  own  eye  can  be  aided  by  magnifying  glasses, 
convex  lenses  of  short  focal  distance  being  used  for  this  purpose. 
The  most  desired  magnification  with  a  large  field  is  obtained,  how- 
ever, only  by  lenses  of  special  construction.  The  Hartnack  spheri- 
cal lens  seems  to  me  particularly  commendable ;  it  is  small,  handy, 
cheap,  has  a  refractive  strength  of  about  35  Diopters,  and  magni- 
fies objects  three  to  four  dimensions. 

More  complete  still,  although  dearer  and  less  easy  to  handle,  is 
the  Zehender-Westien  binocular  lens,  which  magnifies  objects  ten- 
fold and  at  the  same  time  gives  us  stereoscopic  vision.  Aubert's 
binocular  lens  does  the  same  thing. 

To  make  this  examination  with  oblique  illumination  we  need  a 
moderately  dark  room  and  such  a  source  of  light  as  is  ordinarily 
furnished  by  a  lamp  or  an  adjustable  gas  bracket.  The  patient  sits 
at  Yz  in.  from  the  lamp,  which  is  in  front  of  him  and  a  little  to  the 
left.  The  physician  sits  or  stands  in  front  of  the  patient  and  at 
his  right.  With  one  finger  of  his  left  hand  he  raises  the  upper  lid 
of  the  eye  under  examination,  holding  the  lens  between  his  index 
finger  and' thumb.  With  the  right  hand  he  holds  a  convex  lens  of 
about  20  Diopters  so  as  to  throw  an  inverted  reduced  image  of  the 
flame  exactly  upon  the  surface  of  the  cornea,  bringing  it,  therefore, 
at  the  focus  of  the  lens — hence  the  name,  ''focal  illumination."^ 

If  the  lens  is  approached  to  the  eye  the  apex  of  the  cone  of  rays 
falls  upon  different  layers  of  the  cornea.  If  the  lens  is  moved  up- 
ward, downward,  to  the  right  or  to  the  left,  any  desired  spot  on  the 
surface  of  the  cornea  can  be  illuminated  focally.  When  the  condition 

^  This  is  not  exactly  the  proper  term,  for  "  focus  "  really  means  the  focal  point  of  an 
object  lying  on  the  axis  at  infinity. 


lOO  OBJECTIVE    METHODS    OF    INVESTIGATION. 

of  the  cornea  in  all  its  parts  has  been  investigated,  the  lens  can 
be  approached  still  closer  to  the  eye  in  order  to  throw  light  into 
the  aqueous,  upon  the  iris,  into  the  lens,  and,  if  the  pupil  is  wide 
enough,  even  into  the  vitreous. 

Many  diseased  changes  of  the  cornea  stand  out  clearly  by 
mediate  illumination.  For  example,  corneal  blood-vessels  lying  in 
a  faintly  clouded  cornea  can  be  seen  best  if  the  iris  behind  these  spots 
is  illuminated.  The  luminous  rays  are  thus  reflected  from  the  iris 
and  penetrate  the  cornea  from  behind  forward.  In  such  manner 
small  cell  masses  on  the  posterior  surface  of  the  cornea  can  be  dis- 
covered, the  so-called  deposits  on  Descemet's  membrane.  If  these 
are  illuminated  directly,  their  appearance  will  be  obscured  by  the 
light  thrown  back  from  the  corneal  surface  and  from  what  cloudy 
areas  there  may  be  within  the  cornea ;  but  they  are  seen  with  ex- 
traordinary clearness  when  illuminated  from  behind  in  the  method 
just  described. 

In  making  use  of  oblique  illumination  we  see  certain  phenomena  of  liglit  in  their 
physiological  relations.  These  are,  in  part,  images  reflected  from  the  three  refracting 
surfaces  of  the  eye,  the  cornea,  anterior  and  posterior  lens  surfaces  ;  and,  in  part,  light 
diffusely  reflected  from  the  cornea  and  lens.  The  difference  between  these  depends  upon 
the  fact  that  an  area  reflecting  diffused  light  sends  luminous  rays  in  all  directions,  and 
they  are  thus  visible  to  the  observer  irrespective  of  his  relative  position  ;  while  a  mirror 
image  sends  out  a  definite  cone  of  rays  and  is  constantly  visible  to  an  observer  only  when 
his  eye  lies  within  its  path.  Another  difference  is  this  :  Any  part  of  the  cornea  or  lens 
reflecting  diffused  light  appears  a  delicate  gray,  or  in  some  diseased  conditions  even 
white ;  while  a  mirror  image,  particularly  that  of  the  cornea,  is  quite  bright — the  very 
image  of  the  yellow  flame  itself  is  seen.  Whether  the  observer  sees  the  images  or  is 
attracted  more  by  the  areas  reflecting  diffused  light,  depends  somewhat  upon  the  distance 
of  the  convex  lens  from  the  eye  under  examination.  If,  for  example,  the  convex  lens  is 
so  held  that  the  image  of  the  flame  is  focused  in  the  air  nearly  in  front  of  the  cornea,  no 
diffuse  reflection  is  seen,  but  the  images  from  the  three  refracting  surfaces,  the  so-called 
Purkinje-Sanson  images,  appear  more  distinctly  than  in  any  other  method  of  physiological 
demonstration.  Oblique  illumination  is  therefore  undoubtedly  the  best  method  of  demon- 
strating these  three  mirror  images.  If  the  convex  lens  is  approached  closer  to  the  eye, 
the  small  and  distinct  mirror  image  from  the  posterior  lens  surface  is  changed  to  an 
indistinct  yellow  reflection,  particularly  apparent  in  the  eyes  of  old  persons,  and  called 
in  many  text-books,  improperly,  as  I  take  it,  "  nuclear-reflex."  This  reflection  is  not 
from  the  lens  nucleus,  but  from  the  posterior  lens  surface,  and  the  yellow  color  is  due  to 
the  amber-like  appearance  of  the  senile  nucleus. 

If  the  convex  lens  is  held  so  close  to  the  eye  that  the  image  of  the  flame  falls  in  or 
behind  the  crystalline  lens,  one  sees  a  gray  phosphorescent  streak  of  light  in  the  depth 
of  the  pupil.  This  streakiness,  as  well  as  Purkinje-Sanson  images,  may  be  used  to  prove 
the  presence  of  the  lens.  The  cause  of  this  streakiness  has  been  explained  as  being  due 
not  only  to  the  stratified  structure  of  the  lens,  but  also  to  the  fact  that  the  lens  of  itself  is 
not  absolutely  transparent. 


THEORY.  lOI 


III.  THE  OPHTHALMOSCOPE. 

I.  THEORY. 

The  cornea  and  aqueous  being  transparent,  it  is  easy  to  see  the 
iris  lying  behind  them.  The  lens  and  vitreous  are  also  transparent, 
and  yet  the  pupil  is  black,  the  background  of  the  eye  invisible. 
Why  is  this  ?  Until  the  ophthalmoscope  was  devised  the  answer 
ran  as  follows  :  Luminous  rays  entering  the  eye  through  the  pupil 
form  an  optical  image  on  the  retina  and  are  completely  retained 
within  the  eye,  partly  because  they  are  used  up  in  creating  sensa- 
tions of  light,  but  chiefly  because  they  are  absorbed  by  the  pig- 
ment cells  of  the  retina  and  choroid.  As  a  proof  of  this  teaching 
there  was  adduced  the  fact  that  the  pupils  of  so-called  albinos,  white 
rabbits,  for  example,  did  not  appear  black,  but  were  red,  therefore 
luminous. 

This  doctrine  is  easy  to  disprove,  for  the  pupils  of  albinos  appear 
red,  not  on  account  of  light  that  has  entered  the  eye  through  the 
pupil,  but  by  means  of  luminous  rays  that  have  pierced  the  opaque 
coats  of  the  eyeball,  the  sclera,  choroid,  and  retina. 

To  prove  the  above  statement,  take  a  white  rabbit,  put  a  hemispherical  watchglass  over 
its  eye,  and  fill  the  space  between  glass  and  cornea  with  water.  The  glass  should  be 
blackened  till  transparency  is  destroyed,  except  over  a  spot  corresponding  to  the  pupil. 
If  now  the  old  doctrine  were  true,  the  pupil  would  appear  just  as  bright  as  before;  but 
such  is  not  the  case,  for  the  pupil  is  black,  although  perhaps  not  so  black  as  the  pupil  of 
an  ordinary  rabbit.  Now  scratch  the  blacking  off  the  edge  of  the  glass  in  a  semicircular 
spot  about  4  turn,  diameter,  making  the  cornea  visible  behind  it.  By  means  of  a  convex 
lens  throw  on  this  scleral  area  a  strong  beam  of  light  (in  a  dark  room)  from  a  lamp ;  the 
pupil  immediately  appears  bright  red. 

Or  any  eye,  not  an  albino,  may  be  illuminated  thus :  Take  a  rabbit,  dilate  the  pupil 
with  atropin,  and  put  the  animal  into  a  box  holding  the  body  rather  firmly,  but  allowing 
the  head  to  project  somewhat  as  from  a  tight  collar.  In  front  of  the  rabbit's  head  place  a 
lamp  with  an  untransparent  chimney,  but  make  a  spot  on  it  so  that  a  beam  of  light  can  be 
thrown  from  the  lamp  in  one  direction  only  (iita  thoroughly  dark  room,  of  course).  The 
lamp  flame  and  the  orifice  in  the  chimney  are  so  adjusted  that  rays  from  the  flame 
strike  the  rabbit's  eye  from  below  upward.  If  the  observer  places  his  head  close  to  the 
lamp  chimney  and  looks  as  nearly  as  possible  in  the  direction  of  the  connecting  rays  into 
the  rabbit's  pupil,  he  will  find  not  only  that  the  pupil  appears  red,  but  that  the  blood- 
vessels are  visible  within  it. 

The  fact  that  any  eye  is  illuminated  if  the  observer  looks  in  the 
same  direction  as  luminous  rays  entering  it  from  a  flame  was  dis- 
covered in  1846  by  Gumming,  and  independently  in  1847  by 
Bruecke.    v.  Erlach  and  his  friend  Brunner  in  the  winter  of  1846-47 


I02 


OBJECTIVE    METHODS    OF    INVESTIGATION. 


observed  that  they  could  illuminate  the  pupil  with  their  specta- 
cles when  conditions  were  such  that  the  person  under  examination 
saw  in  the  spectacles  of  the  observer  the  reflection  of  a  lamp  in  a 
dark  room.  These  phenomena  were  explained  in  1851  by  Helm- 
holtz,  and  the  ophthalmoscope  was  thereby  discovered. 

It  is  a  universal  law  that  a  reciprocity  exists  in  a  dioptric  system 
between  the  object  and  its  image ;  that  is,  if  the  image  be  considered 
as  the  object,  luminous  rays  will  traverse  the  same  path  backward 
that  they  originally  took,  and  consequently  the  image  will  be  pro- 
duced at  the  place  of  the  original  object.  In  the  eye's  dioptric 
system — cornea,  aqueous,  lens,  vitreous — the  image  of  an  object 
falls  upon  the  retina  if  the  adjustment  is  correct.  Since  luminous 
rays  are  by  no  means  totally  absorbed  by  retina  and  choroid,  that 
part  of  the  fundus  of  the  eye   covered  by  the  image  of  a  point  of 


^i^J^*!P^ 


Fig.  36. — Illumination  in  an  Eye. 
The  luminous  rays  entering  the  eye  under  examination  are  shown  black,  those  returning  from  it  are 


light  becomes  in  its  turn  a  luminous  object,  light  emerges  from  it, 
escapes  in  part  through  the  pupil,  and  produces  at  the  location  of 
the  original  object  an  inverted,  magnified,  though  very  faint  image 
of  the  illuminated  area  of  the  fundus  of  the  eye.  If  by  ordinary 
daylight  we  look  into  the  pupil  of  an  eye,  our  own  pupils  take  the 
place  of  the  bright  object  just  mentioned  ;  but  since  our  own  pupils 
are  not  a  source  of  light,  that  very  area  of  the  eye's  fundus  which 
should  reflect  an  image  back  into  our  pupils  remains  dark,  and  conse- 
quently the  pupil  of  the  person  under  examination  cannot  appear 
luminous. 

It  is  obvious  that  there  are  two  methods  of  making  the  patient's 
pupil  luminous.  One  way  is  that  of  the  experiment  with  the  rab- 
bit just  described.  The  atropinized  rabbit's  eye  is  hyperopic,  and 
therefore  not  adjusted  for  the  flame,  Fl  {Fig.  j6).  The  location  of 
the  flame's  imasfe  is  behind  the  retina  at  Fl'.     On  account  of  circles 


THEORY.  103 

of  diffusion  there  is  on  the  retina  an  illuminated  area,  c  c.  This 
area,  considered  as  object,  emits  rays  diverging-  as  if  they  came  from 
the  far  point  of  the  hyperopic  eye  ;  for  example,  the  point,  a,  sends 
out  rays  (marked  red)  which  appear  to  come  from  a' :  consequently 
they  do  not  all  return  to  their  source  at  the  flame,  but  some  of  them 
strike  the  observer's  eye  placed  near  the  flame.^ 

Indeed,  Fig.  j6  teaches  us  that  the  observer,  if  he  accommodates 
for  a',  ought  to  see  a  part  of  the  fundus  distinctly. 

The  first  method  of  making  the  pupil  luminous  consists  in  illumi- 
nating the  fundus  by  means  of  a  source  of  light  for  which  the  eye 
under  examination  is  not  adjusted. 

The  second  method  consists  in  making  one's  own  pupil  luminous 
by  any  physical  artifice,  that  is,  by  making  it  the  source  of  light  for 
the  eye  under  examination.  We  can  do  this  by  means  of  a  reflect- 
ing glass  disk  and  a  lamp  flame.     The  observer  {Ob,  Fig.  jy)  and 


Fig.  37. — Illumination  of  the  Eye  by  Means  op  a  Glass  Disk. 
The  figure  is  supposed  to  be  in  the  horizontal  plane. 

the  patient  {Pa)  are  opposite  each  other,  and  the  flame  {Fl)  is  in 
the  same  plane  with  their  eyes.  The  observer  holds  the  glass  disk 
before  the  eye  in  such  a  way  that  a  line  perpendicular  to  the  sur- 
face of  the  glass  passes  midway  between  Pa  and  Fl.  Some  of  the 
luminous  fays  falling  from  Fl  upon  the  glass  are,  according  to  the 
known  law,  reflected  as  if  they  came  from  Fl' ;  these  pass,  there- 
fore, into  the  pupil  of  Pa,  appearing  to  come  from  the  pupil  of  Ob. 
But  since  only  a  part  of  the  rays  from  Fl  are  reflected  from  Gl 
(another  part  passes  through  Gl,  and  can,  therefore,  be  neglected  in 
this  experiment),  and  since,  moreover,  the  rays  entering  the  eye,  P<3:, 
are  partly  absorbed  by  the  pigment  cells,  and  still  others  of  those 
returning  from  Pa  are  again  reflected  by  Gl,  it  is  evident  that  but 


^  If  we  trace  the  luminous  pencil  returning  from  the  upper  part  of  the  illuminated  field 
(the  upper  c),  we  find  that  Ol>  can  be  at  quite  a  distance  from  the  flame  without,  getting 
outside  the  range  of  the  returning  cone  of  rays. 


I04  OBJECTIVE    METHODS   OF    INVESTIGATION. 

little  light  finally  reaches  the  observer,  and  that  the  pupil  of  Pa 
will  be  but  faintly  luminous.  Nevertheless,  the  experiment  with 
a  bright  flame  and  a  well-dilated  rabbit's  eye  is  easy  to  make. 
Here,  again,  it  is  possible  to  see  the  fundus  distinctly  if  the  eye 
of  Ob  is  adjusted  for  the  place  from  which  luminous  rays  appear 
to  come.  We  can,  therefore,  say  that  the  fundus  of  the  patient's 
eye  is  distinctly  visible  if  the  luminous  rays  appear  to  come  from 
the  pupil  of  the  observer  when  his  eye  is  adjusted  for  the  appar- 
ent location  of  the  fundus  of  the  eye  under  examination. 

The  devices  for  illuminating  the  fundus  to  be  examined  will  be 
referred  to  on  p.  ii^,  "  Description  of  the  Ophthalmoscope." 
Therefore,  in  the  following  theoretical  explanations  we  may  assume 
this  illumination  as  already  provided  for.  We  need  only  discuss 
here  the  general  conditions  under  which  the  fundus  of  an  eye  can 
be  seen  in  its  upright  image. 

Upright  image.  Direct  method.  The  dioptric  apparatus  of 
the  eye  acts  as  a  convex  lens  of  short  focal  distance  {ig.Sy  imn). 
If  the  retina  lies  within  the  focal  distance  {Fig.  j8,  H)  the  eye  is 
hyperopic,  rays  of  exit  from  the  fundus  are  at  the  cornea  divergent, 
the  image  of  the  fundus,  a'  b',  is  virtual,  upright,  and  magnified. 
The  observer  can  see  it  if  he  accommodates  for  the  location  of  the 
image. 

If  the  posterior  focal  point,/,  lies  exactly  on  the  retina  {Fig.  j8,  E) 
the  eye  is  emmetropic,  all  rays  emerge  from  the  cornea  parallel,  an 
image  is  formed  at  infinity  (that  is,  not  at  all).  The  observer  can, 
however,  see  the  fundus  if  he  is  emmetropic  and  does  not  accom- 
modate, for  in  such  a  case  all  rays  in  passing  through  the  refractive 
media  of  the  eye  form  an  image  on  the  retina  of  his  own  eye. 

Finally,  if  the  retina  lies  behind  the  posterior  focal  point  (/v^.j^, 
M)  the  eye  is  myopic,  all  rays  emerge  from  the  cornea  converging 
to  the  far  point  of  the  eye  under  examination.  The  observer,  sup- 
posed to  be  close  in  front  of  the  cornea  of  the  patient's  eye,  can 
receive  on  his  own  retina  the  image  of  the  other's  fundus  only 
when  he,  himself,  is  hyperopic,  and  only  when  the  (virtual)  far  point 
of  the  hyperopic  observer  coincides  with  a',  the  actual  far  point  of 
the  myopic  eye  under  examination. 

Therefore,  to  be  able  to  examine  the  upright  image  of  the  fundus 
of  any  eye,  the  observer  must  be  capable  of  making  his  own  eye 
emmetropic,  hypermetropic,  or  myopic,  at  will.  The  last  is  the 
easiest.     With  the  aid  of  accommodation  the  hyperope  and  the 


THEORY. 


105 


emmetrope  and,  of  course,  the  myope  can  adjust  the  eye  for  a  near 
object,  because  the  mechanism  of  accommodation  can  perceive  by 
instinct  that  adjustment  which  will  give  the  clearest  vision.  The 
myopic  observer  can  make  himself  emmetropic  by  a  neutralizing 
concave  lens ;  the  hyperope  can  accomplish  the  same  result  by  a 
convex  lens  or  by  a  proper  effort  at  accommodation.  Moreover,  if 
the  eye  under  examination  is  myopic,  the  emmetropic  observer 
needs  a   concave  lens  to  make  him  proportionally  hyperopic  ;  a 


<C__ 


Fig.  3S. — Examination  of  the  Upright  Image,  in  Hyperopia,  Emmbtropia,  and  Myopia. 
y"is  the  posterior  focal  point,  the  red  line  is  the  axis. 


myopic  observer  needs  for  the  same  purpose  a  concave  lens 
increased  in  strength  by  the  amount  of  his  own  myopia ;  a 
hyperopic  observer  must  increase  his  own  hyperopia  by  such  a 
concave  lens  or  decrease  it  by  such  a  convex  lens  as  will  make  his 
(negative)  far  point  coincide  with  the  far  point  of  the  eye  under 
examination. 

Fig.  j8  shows  us  that  the  refractive  condition  of  the  eye  under 
examination  influences  the  magnification  at  which  the  fundus  of 
that  eye  appears  to  the  observer.     The  stronger  the  hyperopia,  the 


io6 


OBJECTIVE    METHODS    OF    INVESTIGATION. 


closer  to  the  actual  fundus  lies  the  virtual  image  of  the  fundus  seen 
by  the  observer,  and  the  less  is  the  difference  to  him  between  the 
size  of  the  object  and  the  size  of  the  image.  In  case  the  eye  under 
examination  is  myopic,  the  relations  are  not  quite  so  evident,  but  it 
can  be  shown  by  a  simple  construction  that  in  this  case  the  mag- 
nification is  more  pronounced  than  when  the  eye  is  emmetropic. 

In  Fig.  jg.  Pa  is  the  eye  of  the  patient  and  is  at  first  emmetropic  ;  the  red  arrow 
pointed  downward  represents  an  area  of  his  retina.  One  ray  from  the  tip  passes  appa- 
rently unrefracted  through  the  nodal  point,  ku  ;  all  others  emerge  from  the  cornea  of  Pa 
parallel  to  the  first  one.  These  rays,  if  they  enter  the  pupil  of  an  observer's  eye  adjusted 
for  infinity,  must  intersect  at  a  point  of  the  retina  of  Ol>,  which  is  found  by  drawing 
through  kc  a  line  (dotted  red)  parallel  to  the  ray  (continuous  red)  of  entrance.  Suppose 
Pa  is  now  myopic ;  the  black,  arrow  pointed  downward  represents  an  area  of  his  retina ; 
rays  passing  out  from  the  arrow  tip  would  form  an  image,  r,  at  the  far  point  if  the  observer 
did  not  intercept  them,  but  on  passing  through  the  refractive  media  of  Ob,  whom  we 
assume  now  to  be  proportionately  hyperopic,  they  form  an  image  on  his  retina  which 
must  lie  on  the  line  of  connection  between  kc  and  r.  We  see  now,  that  the  black  upright 
arrow  is  decidedly  larger  in  Ol>  than  the  red  one,  that  the  former  must  be  relatively 
increased  in  size  the  nearer  r  is  ;  that  is,  the  stronger  the  myopia  of  Pa. 


jy 

JI 

^ 

^s<^ 

-^'^ 

n^"^ 

j'-'^n 

.^■-'-' 

"'\ 

\a^^ ^'^ 

I— ^ 

''"''' \ 

K 

^^^^ 

H-'' 

M 

v_ 

^06 

Fig.  3y. — Comparison  of  the  Magnification  in  an  Emmetropic  Eye  and  in  a  Myopic  Eye. 


Inverted  Image.  Indirect  Method. — Fig.  j8  {M)  shows  us 
that  we  can  see  the  fundus  of  a  myopic  eye  without  concave  lenses. 
The  observer  need  only  retire  (to  the  right)  from  the  patient  till 
he  is  beyond  the  image,  a'  b',  which  is  in  the  air,  inverted,  actual, 
and  magnified,  when  he  will  perceive  it  if  he  uses  his  accommoda- 
tion for  the  location  of  this  image.  He  sees  an  inverted  image,  and 
on  this  account  the  method  is  called  the  "  examination  of  the 
inverted  image."  It  is  evident  that  this  examination  is  possible 
without  the  use  of  other  means  only  when  the  myopia  is  of  a  high 
degree,  for  the  lower  the  myopia,  the  larger  and  consequently  the 
dimmer  will  be  the  aerial  image,  a'  b',  and,  therefore,  the  smaller  will 
be  the  area  of  the  fundus,  whose  image  is  at  one  time  visible  to 
the  observer.  But  there  is  a  very  simple  method  of  making  any 
eye  artificially  myopic  ;  for  this  purpose  we  use  a  convex  lens. 
Ruete  first  introduced  this  practice  into  ophthalmology,  and   since 


THEORY. 


107 


then  the  examination  of  the  inverted  image  has  been  generally 
applied.  Fig.  4.0  illustrates  the  principle  for  the  three  cases — hyper- 
opia (//),  emmetropia  {E),  and  myopia  {M). 

The  drawing  indicates  that  the  refractive  condition  of  the  eye 
under  examination  has  an  influence  on  the  size  of  the  resulting  in- 
verted image.  The  rays  from  the  myopic  eye,  J/,  already  conver- 
gent when  they  strike  the  convex  lens,  5  S,  are  the  soonest  to  be 
united  at  a  focus,  and,  therefore,  the  smallest  image   is  the  result. 


Fig.  40. — Examination  of  the  Inverted  Image,  in  Hyperopia,  Emmetropia,  and  Myopia. 
y  is  the  posterior  focal  point,  the  red  line  is  the  axis. 


The  rays  from  the  hyperopic  eye,  H,  divergent  when  they  strike  the 
convex  lens,  6"  S,  are  the  last  to  be  united,  and  therefore  the  largest 
image  is  the  result.  The  rays  from  the  emmetropic  eye,  E,  are 
parallel  when  they  strike  the  convex  lens,  6"  kS",  and  the  result  is  an 
image  of  a  size  midway  between  the  two  others. 

Amount  of  magnification  of  the  upright  image.  The  upright  image  is  a  virtual  one  ; 
consequently  its  size  cannot  be  compared  with  the  size  of  the  actual  image  without  some 
explanation.  This  comparison  is,  however,  not  essential,  since  we  obtain  a  good  answer 
to  the  question  as  to  the  ophthalmoscopic  magnification  by  comparing  the  visual  angle 
at  which  an  object  (the  optic  disc,  for  example)  appears,  if  it  is  in  one  case  examined  at  a 


io8 


OBJECTIVE    METHODS    OF    INVESTIGATION. 


definite  distance  as  an  anatomical  preparation,  and  in  another  case  as  a  living  object  seen 
through  the  refractive  media  of  the  eye  under  examination  ;  that  is,  in  the  upright  image. 

This  "definite  distance  "  should  be  the  distance  of  the  observer's  near  point.  At  the 
near  point  of  our  eyes  objects  appear  under  the  greatest  practical  visual  angle  ;  but  the 
near  point  differs  in  different  individuals  according  to  the  age,  and  we  are  accustomed  by 
experience  to  bring  objects  that  we  wish  to  examine  most  exactly  not  precisely  to  the 
near  point,  but  to  a  distance  of  20  to  jo  an.,  youthfulness  of  the  observer  being  assumed. 
The  question  as  to  the  ophthalmoscopic  magnification  becomes  therefore  the  following : 
What  is  the  relation  of  the  visual  angle  under  which  the  virtual  image  of  the  optic  disc 
appears,  to  that  visual  angle  under  which  the  disc  itself  appears  at  a  distance  of  2^  cm.  ? 
In  case  the  patient  (/'«,  Fig.  41)  and  the  observer  {Ob,  Fig.  41)  are  both  emmetropic, 
the  answer  will  be  as  follows : — 

Let  a  {Fig.  41,  II)  be  250  7nm.  from  the  principal  plane,  //  //,  and  the  size  of  the 
object,  a  b,  be  /.j  7nm.  The  object  then  appears  under  a  visual  angle  of  — ^~ — ,  since  on 
the  one  hand,  we  have  assumed  the  distance  of  the  nodal  point  from  the  principal  plane  to 
be  J  mm.,  and  on  the  other  hand  we  can  use  the  trigonometrical  tangent  instead  of  the 
angle  itself,  all  angles  being  so  small  in  this  instance.    But  if  «  b  is  looked  at  through  the 


Fig.  41. — Mac.nification  of  the  Upright  Image  in  an  Emmetropic  Eve. 


dioptric  apparatus  of  the  eye  under  examination  {Fig.  41,  I)  acting  as  a  lens,  then,  as  the 

b  '  a  ' 
figure  shows,  the  visual  angle  is  equal  to  ^^^-^ — ,.    The  similarity  of  the  triangles,  b'  a'  A'' 

b'a'  ba  is 

and  ^  rt  A',  makes  ir=-, — ;  =  -f^ —  =  — -^.     This  last  equation  is  17  times  greater  than 
'  K'a'  Ka  15  '  /  s 

— '- — ,  and  the  magnification  is,  therefore,  a  seven teenfold  one. 
255  '  ^  ' 

In  the  second  case  {Fig.  42),  when  the  patient's  eye  is  axis  myopic,  let  the  myopia  be 

of  J  o  £>.     Then  the  disc  lies  /.6  mm.  behind  the  posterior  principal  focal  point,/",  and 

the  far  point,  a  '',  is  200  mm.  in  front  of  the  principal  plane,  H H  {Fig.  42).     Let  the 

observer  {Ob)  be  40  mm.  away  from  the  patient  (/'«).   Under  these  conditions  the  hyper- 

opic  Ob,  having  a  virtual  far  point  at  a  ' ,  sees  the  arrow,  <z  ^,  at  a  visual  angle,      ,   ^,  r=. 

^-^ — y     The  denominator,  K'  a' ,  with  our  assumption  above,  is  equal  to^oo — 40 — -j  = 

^55  Mm. ,  if  we  take  the  distance  of  the  nodal  point,  K' ,  from  the  principal  plane,  II'  H' , 

to  be  J  mm.    The  numerator  can  be  determined  by  means  of  a  pair  of  equal  triangles,  as 

shown  in  the  figure  {a  b  K^=  a'  b'  K')  to  be  -^^  X  203  mm.     The  equation  then  reads 

X  -?^  :=  -^— .     Since  «  i^,  at  a  distance  of  2^0  mm.,  appears  to  Ob,  without  the 

,  and  since  -^-^  is  20.^ 


205    

'55  -J      .  .  1.5 

magnification  of  the  patient's  eye,  at  a  visual  angle  of 


'•5 

16.6 


times  greater  than ,  we  find  the  desired  magnification  to  be  20.^, 


8.3 


TH  EORY. 


109 


By  a  corresponding  process  we  find  the  magnification  for  a  case  where  the  patient  has 
j-.o  D  hyperopia  and  the  (myopic)  eye  is  40  fnm.  distant  from  Pa  to  be  a  fifteenfold  one. 

Aiitotntt  of  magnification  of  the  inverted  image.  Assume  the  patient  to  be  emmetropic. 
To  obtain  the  inverted  (aerial)  image  use  a  convex  lens  of  20.0  D  {^  m.=  jomm.) 
focal  distance.  Since  rays  emerging  from  an  emmetropic  eye  are  parallel,  the  aerial  image, 
a'  b'.  Fig.  4J,  falls  at  the  focal  distance,  JC'  a',  of  the  lens;  and  since,  with  the  above 


J'a.AC.  (MM. 

Fig.  42. — Magnification  of  the  Upright  Image  from  a  Myopic  Eye. 


assumptions,  the  ray  of  direction,  b  K,\vi  the  emmetropic  eye.  Pa,  is  parallel  to  the  ray  of 

direction,  K'  b',  of  the  lens,  5' 5,  the  triangle  a  b  K  being  thus  equal  to  the  triangle 

aba'b' 
a  '  b  '  K ',  then  — — -  =  — r-rr-r- ;  and  since 

a  K  a  '  K  ' 

a  b  ^=--  I.J  fnm. 

a  JC  =  ij   mm. 

a  '  K '  =^  JO   fnm., 

then  a  '  b  ^  =z  '"^  X  5°  =  J"  mfti.;  in  other  words,  the  aerial  image  of  Ob  is  j"  fnm.  in 
size,  about  J.J  times  larger  than  the  object,  the  disc.  Since  we  are  treating  here  of  actual 
and  directly  comparable  images,  there  is  no  need  of  considering  the  visual  angle,  and  we 
can  say  at  once  that,  with  the  above  assumptions,  the  magnification  is  a  j.j-fold  one. 

By  Fig.  4j  we  can  further  perceive  that  the  distance  of  the  lens,  S  S,  from  the  emme- 
tropic eye.  Pa,  is  immaterial,  and  that  the  magnification  increases  with  a  weak  lens  and 
decreases  with  a  strong  one.     Suppose  a  lens  2A.  K '  with  twice  the  refractive  power  of 


Fig.  43. — Magnification  op  the  Inverted  Image. 


S  S;  then  the  image,  b  "  a  " ,  falls  at  K'  a  '' ,  just  half  the  distance  of  K  '  a  '.  There- 
fore the  image,  b  "  a  ",  is  half  the  size  oi  b  '  a  ' ,  and  the  magnification  only  one  and  a 
half  that  of  .S"  S.  If  Pa  has  a  myopia  of  j.o  D  and  the  lens  {20.0  D)  is  40  mm.  from  the 
principal  plane  of  Pa,  by  the  same  reasoning  we  find  an  aerial  image  of  the  disc  to  be 

4  4  mm. ,  about  a  threefold  linear  magnification.  With  hyperopia  of  5.0  D,  and  the  lens 
at  40  fnm.  distance,  the  aerial  image  of  the  discis  j.6  fnm.  long,  a  j.7-fold  magnification.. 

If  the  lens,  S  S,  is  placed  so  far  from  Pa  that  its  focal  point  coincides  with  the  anterior 
focal  point  of  Pa,  the  refractive  condition  of  Pa  will  have  no  influence  upon  the  magnifi- 
cation ;  in  emmetropia,  hyperopia,  and  myopia  it  is  the  same.     With  the  focal  point  of 

5  S  falling  outside  the  focal  distance  of  Pa  the  conditions  change,  the  magnification  is 


no  OBJECTIVE    METHODS    OF    INVESTIGATION. 

weakest  in  hyperopia  and  strongest  in  myopia.      (Farther  analysis  is  unnecessary,  since 
such  problems  are  seldom  applied  in  ophthalmoscopy.) 

Ophthalmoscopic  Field  of  Vision. — 

(/)    Upright  image. 

(^)  Inverted  image. 

(/)  Upright  image.  That  part  of  the  patient's  fundus  which 
the  observer  is  able  to  see  at  one  and  the  same  time  is  called  the 
ophthalmoscopic  field.  The  question  of  its  size  can  be  best  an- 
swered by  applying  the  law  of  reciprocity.  Every  point  in  the 
patient's  fundus  sends  luminous  rays  into  the  observer's  pupil, 
every  point  of  the  observer's  pupil  receives  these  rays  if  they  are 
luminous;  in  short,  the  ophthalmoscopic  field  is  coincident  with 
that  diffusion  image  of  the  observer's  pupil  which  is  made  upon  the 
fundus  of  the  patient's  eye.  To  construct  the  image  of  the  pupil, 
Pp  {Fig.  ^4),  upon  the  fundus  of  the  patient's  eye,  draw  lines  from 
P  and  /  of  Ob  through  the  nodal  point  K  to  the  retina  of  Pa.  Then 
p'  P'  is  the  image  of  Pp,  in  case  Pa  is  adjusted  for  Pp,  which  is 
obviously  not  always  so.     Consequently  every  point  of  Pp  may 


Fig.  44. — The  Ophthalmoscopic  Field  op  Vision,  Upright  Image. 

produce  on  the  patient's  fundus  a  diffusion  circle  instead  of  an  exact 
image.  The  red  lines  represent  the  diffusion  circle  ^^  of  the  point 
P,  assuming  the  patient  to  be  emmetropic  and  free  from  accommo- 
dation. If  this  is  taken  for  granted,  it  is  a  simple  matter  to  deter- 
mine the  four  conditions  which  influence  the  size  of  the  ophthal- 
moscopic field. 

{a)  The  size  of  the  observer's  pupil  must  be  considered,  since  the 
greater  Pp  is,  the  greater  will  be  the  image  p'  P  on  the  fundus  of 
the  patient's  eye.  As  a  matter  of  fact,  the  size  of  the  observer's 
pupil  becomes  of  no  consequence  by  reason  of  the  small  hole  in 
the  ophthalmoscope  that  is  always  placed  before  the  observer's 
eye.  This  hole  in  the  mirror,  therefore,  plays  the  part  of  the 
observer's  pupil  in  Fig.  4^. 

ib)  The  distance  of  observer  from  patient  is  of  great  significance ; 


THEORY.  I  I  I 

because,  as  the  patient  is  approached,  the  hole  in  the  mirror  is 
brought  closer  and  allows  a  larger  image  to  be  thrown  on  the 
patient's  fundus.  The  practical  rule,  then,  in  the  examination  of  the 
upright  image  takes  no  account  of  the  size  of  the  observer's  pupil, 
but  emphasizes  the  importance  of  approaching  as  close  as  possible 
to  the  patient. 

[c)  The  size  of  tJie  patient's  pupil  \^  also  of  great  significance.  It 
must  be  as  dilated  as  possible,  by  closing  the  other  eye,  shutting 
off  unnecessary  light  (dark  room),  excluding  light  from  the  most 
sensitive  part  of  the  fundus  (macula  lutea),  or,  if  necessary,  by  the 
use  of  a  mydriatic.  That  the  ophthalmoscopic  field  is  enlarged  and 
the  examination  facilitated  by  a  dilated  pupil  is  seen  in  Fig.  ^^.  A 
narrow  pupil  in  the  patient  cuts  off  some  of  the  rays  and  diminishes 
the  size  of  the  diffusion  circle,  s  z'. 

[d)  TJie  position  of  tJie  point  f 07'  tvhicJi  tJic  patienfs  eye  is  acconi- 
modated  has  the  most  direct  influence  upon  the  size  of  the  diffusion 
image  of  Pp,  and  therefore  upon  the  size  of  the  field.  Obviously 
the  diff"usion  increases  equally  as  the  point  of  accommodation  in 
the  patient's  eye  is  withdrawn  (toward  the  right  in  the  figure  );  if 
this  reaches  infinity,  that  is,  if  the  patient  is  emmetropic,  the  field 
is  greater  than  that  of  any  myopia  ;  in  hyperopia  it  is  the  greatest, 
the  point  of  accommodation  being  beyond  infinity.  Hence  we  may 
conclude  that  in  tlie  examination  of  the  upright  image  the  ophthal- 
moscopic field  increases  zvith  increasing  hyperopia  and  decreases  with 
increasing  myopia. 

In  this  study  of  the  size  of  the  ophthalmoscopic  field  it  is  always 
taken  for  granted  that  the  entire  fundus  of  the  patient's  eye  emits 
light.  This  is  not  always  so.  In  practice  we  find,  often  enough,  that 
only  a  small  part  of  the  field  is  illuminated,  or  consequently  luminous 
and  visible.  The  character  of  the  mirror,  the  size  and  distance  of 
the  flame,  are  here  the  most  important  factors. 

The  increase  of  the  field  with  corresponding  decrease  in  magnitication  of  the  image 
can  be  demonstrated  as  follows :  On  the  atropinized  eye  of  a  rabbit  place  a  small  glass 
cylinder  whose  base  is  covered  with  a  sheet  of  mica  ;  fill  the  space  between  cornea  and 
mica  with  water.  The  cornea  is  thereby  obliterated  (optically)  and  the  eye  made  strongly 
hyperopic  ;  we  see  now  a  large  area  of  the  fundus  scarcely  magnified  at  all.  Since  the 
virtual  image  of  the  fundus  lies  relatively  close  behind  the  actual  fundus,  the  most  inex- 
perienced observer  can  easily  accommodate  for  this  image.  The  experiment  is  a  good 
introduction  to  the  study  of  ophthalmoscopy. 

The  conditions  are  the  same  after  cataract  operations ;  but  as  the  lens  has  only  one- 
fourth  the  refractive  power  of  the  cornea,  the  hyperopia  is  not  so  great  as  it  is  when  the 
cornea  is  obliterated. 


112  OBJECTIVE    METHODS    OF    INVESTIGATION. 

{2)  Im>erted  Image.  In  this,  also,  the  ophthalmoscopic  field  is 
coincident  with  the  (diffusion)  image  of  the  observer's  pupil  on 
the  fundus  of  the  patient's  eye  ;  but,  on  account  of  the  interposi- 
tion of  the  convex  lens,  it  is  much  larger  than  in  the  examination 
of  the  upright  image.  If  the  lens  is  held  properly  the  size  of  the 
patient's  pupil  has  no  influence,  the  size  of  the  observer's  pupil 
very  little  influence,  so  that  it  is  unnecessary  to  study  these  factors 
further.  But  the  size  of  the  lens  and  its  focal  distance  and  the 
refractive  condition  of  the  patient's  eye  are  of  the  greatest  import- 
ance.    This  is  easily  perceived  in  Fig.  /f.^} 

Here  the  pupil  of  the  observer  is  assumed  to  be  a  point.  A  pen- 
cil of  rays  proceeding  from  it  would,  on  account  of  the  relatively 
great  distance  between  Ob  and  the  lens,  ^  S,  be  united  close  behind 
/",  the  focus  o{  S  S.  If  now  the  lens  is  so  held  that  its  focal  point 
falls  just  in  front  of  the  plane  of  the  patient's  pupil,  the  image  of  / 
will  lie  at  or  close  behind  this  plane ;  and,  consequently,/'  P  will  be 


Fig.  45. — The  Ophthalmoscopic  Field,  Inverted  Image. 

the  diffusion  image  of  p,  if  the  patient  is  hyperopic,  or  p"  P"  if  he 
is  myopic. 

Without  going  further,  it  is  seen  that  the  size  of  the  patient's 
pupil  is  without  significance  if  the  point  of  intersection,  ^,  lies  near 
the  pupillary  plane,  and  that  the  ophthalmoscopic  fields,  p'  P'  and 
p"  P",  become  somewhat  larger  when  the  observer's  pupil  is  dila- 
ted. Every  point  of  his  pupil  will  then  produce  just  such  a  field, 
p'  P ,  and  the  individual  fields  will  only  in  part  be  coincident. 

The  influence  of  the  size  of  ^  .S  is  shown  in  the  coloring  in  Fig.  ^j. 
If  S  6"  is  made  small  by  reducing  it  to  S'  S' ,  then  only  the  areas, 
r'  t:'  or  tt"  -",  receive  rays  from  p  and  are  perceptible.  The  influ- 
ence of  the  focal  distance  can  be  recognized  by  the  fact  that  with  a 
shorter  focal  distance  the  lens,  S  S,  would  have  to  be  approached 
closer  to  the  patient  in  order  to  throw  the  image  of  the  observer's 

^  For  the  sake  of  clearness,  it  is  assumed  that  the  rays  converging  to  the  point,  d,  pro- 
ceed further  in  a  straight  line.  As  a  matter  of  exactness  this  is  correct  only  when  d  coin- 
cides with  the  nodal  point.  But  there  is  obviously  no  radical  error  in  using  this  license 
in  a  text-book. 


THEORY,  I  I  3 

pupil  on  to  or  close  to  the  patient's  pupil ;  but  the  nearer  ^  5  is  to 
the  patient,  the  greater  is  the  angle  at  d,  and  therefore  the  greater 
\sp'  P'. 

The  influence  of  the  refractive  condition  of  the  patient's  eye  can  be 
seen  in  the  fact  that  -'  tz'  is  smaller  than  r."  tJ\  a.nd  p'  P'  is  smaller 
than/"/"'.  The  hyperopic  eye  (/>'  t' t:'  P')  admits  of  a  smaller 
ophthalmoscopic  field,  ceteris  paribus,  the  myopic  eye  {p''tz" 
_n  pt  f^  ^  larger  ;  the  emmetropic  eye  a  medium  field — //le  size  of  the 
ophthalmoscopic  field  increases  with  increasing  myopia,  diminisJies 
with  increasing  hyperopia. 

In  practising  the  examination  of  the  inverted  image  the  proper 
distance  for  the  lens  is  found  by  observing  the  image  of  the  pa- 
tient's iris.  If  the  convex  lens  is  held  too  far  from  the  patient, 
that  is,  if  its  focal  point  falls  in  front  of  his  eye,  the  observer  sees 
an  inverted  image  of  the  iris ;  if  it  is  held  too  near,  he  sees  a  vir- 
tual upright  image;  and  if  it  is  held  just  right,  that  is,  so  as  to 
throw  the  focal  point  the  smallest  distance  in  front  of  the  pupillary 
plane,  he  sees  no  iris  image.  It  is  best,  therefore,  to  move  the  lens 
back  and  forth  till  the  iris  image  disappears,  when  the  largest  field 
will  be  visible. 

When  it  was  said  that  if  the  lens  were  held  properly  the  size  of  the  patient's  pupil 
bad  no  significance,  it  had  reference  only  to  the  theoretical  ophthalmoscopic  field,  it  being 
taken  for  granted  that  the  entire  fundus  of  the  patient's  eye  emitted  light.  This  assump- 
tion is  practically  not  fulfilled.  On  the  contrary,  the  ordinary  concave  mirror  illumi- 
nates only  a  part  of  the  ophthalmoscopic  field  and  makes  it  perceptible.  Practically,  then, 
the  size  of  the  patient's  pupil  plays  an  important  part  in  the  examination  of  the  inverted 
image.  The  beginner  finds  it  hard  or  even  impossible  to  see  the  fundus  of  the  patient's 
eye  if  the  pupil  be  small.  The  principal  reason  for  this  lies  in  the  fact  that,  as  the  pupil 
contracts,  the  brightness  of  the  illuminating  field  (in  the  fundus  of  the  patient's  eye) 
decreases,  while  the  quantity  of  light  reflected  from  the  cornea  remains  unaltered.  The 
corneal  reflex,  therefore,  rather  obscures  the  image  of  the  fundus. 

From  what  has  been  said,  especially  from  the  examples  given, 
we  see  that  the  ophthalmoscopic  magnification  is  decidedly  larger 
in  the  examination  of  the  upright  image  than  in  that  of  the  in- 
verted image;  and  further,  that  this  magnification  on  the  one  hand, 
and  the  extent  of  the  field  on  the  other,  stand  somewhat  in  opposi- 
tion to  each  other.  A  good  working  rule  may  be  deduced  from 
this — first,  to  examine  the  inverted  image  of  the  fundus  to  get  the 
largest  possible  view  of  it  and  its  condition,  and  then  to  proceed  to 
the  examination  of  the  upright  image  in  order  to  study  the  details 
with  the  highest  possible  magnification. 
8 


114 


OBJECTIVE    METHODS    OF    INVESTIGATION. 


2.  DESCRIPTION  OF  THE  OPHTHALMOSCOPE. 
Although  Helmholtz's  original  ophthalmoscope  is  now  used 
only  for  particular  purposes,  we  should  honor  its  discoverer  by 
describing  his  instrument  first  {Fig.  46).  It  consists  of  a  disk  of 
three  reflecting  glass  plates,  a,  which  form  the  oblique  end  of  a 
brass  tube,  b,  and  of  an  adjustment  at  the  other  end  for  putting  in 
place  a  concave  lens,  c.  The  whole  is  held  by  a  handle  (not  shown 
in  the  figure).  The  observer  at  d  looks  into  the  square  end  of  the 
tube  through  the  glass  plates  toward  the  patient's  eye.  The  visual 
axis  cuts  the  glass  plates  at  an  angle  of  jo°.  In  order  that  the 
luminous   rays  coming  from   the   lamp   may  be   reflected   in  this 

direction,  they  must  have  an  incident 
angle  of  <5o°,  an  arrangement  possible 
only  when  the  lamp  is  placed  quite  at 
one  side.  This  inconvenience  must 
be  put  up  with  for  the  sake  of  the  ad- 
vantage gained  by  the  strongest  pos- 
sible illumination  of  the  fundus  with 
the  weakest  possible  reflex  of  the 
cornea. 

Helmholtz's  ophthalmoscope  gives, 
however,  under  the  best  of  circum- 
stances, but  feeble  illumination.  For 
this  reason  Epkens  used  a  glass  disk 
with  a  coating  on  the  back,  a  genuine 
mirror,  in  which  a  small  hole  was  scratched  for  the  observer  to  look 
through  ;  but  since  there  was  still  a  reflex  from  the  uncovered  bit 
of  glass,  which,  while  it  absorbed  light,  also  confused  the  observer  by 
throwing  part  of  this  reflex  into  his  eye,  the  method  was  adopted 
of  boring  a  hole  through  the  glass  itself.  This  hole  formed  a  small 
canal  through  the  thickness  of  the  glass,  and  its  walls  had  to  be 
well  blackened  in  order  to  avoid  any  confusing  reflex  from  them. 
This  could  not  be  completely  overcome  unless  the  canal  were 
made  very  short,  which  was  possible  if  a  polished  plate  was  used 
instead  of  glass. 

Even  with  these  improvements  the  plane  mirror  is  still  of  feeble 
illumination.  For  this  reason  Ruete,  to  whom  we  also  owe  "the 
examination  of  the  inverted  image,"  made  use  of  the  stronger  con- 
cave mirror.     This  gives   in   front  of  its  reflecting  surface  an  in- 


FiG.    46. — Helmholtz's    Ophthalmo- 
scope IN  Horizontal  Section. 
The  arrows  indicate  the  path  of  the  inci- 
dent rays. 


DESCRIPTION    OF    THE   OPHTHALMOSCOPE. 


115 


verted,  reduced,  actual  image  between  mirror  and  patient;  the 
plane  mirror,  on  the  contrary,  gives  an  upright,  virtual  image  be- 
hind the  mirror,  that  is,  an  image  at  a  greater  distance  from  the 
patient.  It  is  evident,  then,  that  the  concave  mirror  throws  a  greater 
quantity  of  light  into  the  patient's  pupil,  although  this  does  not 
imply  that  the  retinal  area  illuminated  by  the  concave  mirror  is 
brighter  than  can  be  obtained  by  the  use  of  a  plane  mirror.  The 
circumstances  influencing  this  condition  are,  however,  too  numer- 
ous to  be  disposed  of  in  a  few  words. 

The  concave  mirror  most  used,  on  account  of  its  handy  shape 
and  small  price,  is  that  of  Liebreich  {Fig.  ^7).  Its  focal  distance 
is  generally  between  i^  and  20  cm.     On  the  blackened  frame  sur- 


FiG.  47. — Liebreich's  Ophthalmoscope. 


rounding  the  mirror  is  a  small  adjustable  arm, 
a,  bearing  a  semicircular  clip,  b,  into  which 
lenses  of  different  strengths,  c,  can  be  placed. 
The  case  provided  with  the  instrument  usu- 
ally contains  five  of  these.  There  are,  besides, 
two  convex  lenses  of  ij.o  D  and  20.0  D, 
which  can  be  used  both  for  examination  of  the  inverted  image  and 

for  focal  illumination.  

As  a  rule,  the  weak  plane  mirror  is  to  be  preferred  to  the  strong 
concave  mirror.  Jaeger  devised  an  ophthalmoscope  in  which 
either  a  plane  or  a  concave  mirror  could  be  introduced  at  will. 
Coccius  obtained  the  same  result  by  combining  a  plane  mirror 
with  a  convex  lens,  the  latter  being  replaceable  by  one  of  stronger 
or  weaker  focal  distance  as  might  be  required,  and  according  to 
choice,  the  effect  of  a  concave  mirror  of  great  or  small  focus  was 
produced.  If  the  convex  lens  was  removed  there  remained  only 
the  action  of  a  plane  mirror. 


ii6 


OBJECTIVE   METHODS    OF    INVESTIGATION. 


Zehender  accomplished  a  similar  result  by  combining  a  convex 
lens  of  about  lo.o  D  with  a  convex  mirror ;  in  this  ophthalmo- 
scope changing  the  distance  of  lens  from  mirror  produced  the 
same  effect  as  changing  the  lenses  in  Coccius'  instrument. 

An  essential  advance  was  marked  by  the  introduction  of  the 
refraction  ophthalmoscope.  Fig.  48  illustrates  one  of  the  best  of 
its  kind.     The  principle  of  it  is  the  same  as  that  of  the  simple 


Fig.  48. —  Refraction  Ophthalmoscopk. 


Liebreich  instrument.  It  has  the  added  advantage  that  behind  the 
sight-hole  there  can  be  introduced  lenses  of  varying  strength 
mounted  in  a  rotating  disk. 

There  are  innumerable  ophthalmoscopes.  Many  are  but  modi- 
fications of  the  above ;  some  introduce  other  optical  principles ; 
others,  such  as  the  instrument  to  examine  one's  own  eyes,  or  the 
binocular  ophthalmoscope,  serve  a  particular  purpose.  They  need 
no  description  here. 


USE    OF   THE    OPHTHALMOSCOPE.  II7 

3.  USE  .OF  THE  OPHTHALMOSCOPE. 
The  ophthalmoscope  serves  four  purposes — 

(A)  To  discover  and  to  detertnine  the  location  of  opacities  in  the  re- 
fractive media  ; 

(B)  To  study  the  fmtdiis  ; 

{C)   To  determine  the  refraction  condition  ; 

{D)   To  demonstrate  differences  in  level  in  the  fundus. 

In  using  the  ophthalmoscope  the  observer  sits  in  a  dark  room 
about  ^o  cm.  in  front  of  the  patient.  By  the  side  of  and  somewhat 
behind  the  eye  to  be  examined  is  the  source  of  light,  which  may 
be  an  oil  lamp  or  a  gas  flame ;  the  flame  should  be  large  in  any 
case.  The  source  of  light,  the  eyes  of  observer  and  patient,  should 
all  be  in  about  the  same  horizontal  plane ;  it  is  therefore  of  advan- 
tage to  have  lamp  and  stools  for  the  physician  and  patient  that  can 
be  raised  and  lowered.  It  is  advisable  for  the  physician  to 
accustom  himself,  when  making  examinations  of  the  upright 
image  at  least,  to  use  his  right  eye  for  the  patient's  right  eye,  and 
his  left  for  the  patient's  left  eye,  since  this  is  the  only  way  to  get 
closest  to  the  eye,  and  the  discomfort  of  rubbing  noses  is  thereby 
avoided.  It  must  be  acknowledged,  however,  that  most  ophthal- 
mologists do  examine  the  patient's  left  eye  with  their  right. 
Another  good  plan  is  for  the  patient  to  turn  his  face  toward  his 
right  while  continuing  to  look  straight  ahead,  since  in  this  way  his 
nose  is  brought  to  the  side  of  the  nose  of  the  examiner. 

The  patient  is  now  asked  to  stare  vacantly  at  the  physician's  right 
ear  if  the  patient's  right  eye  is  to  be  examined,  at  the  left  ear  if  the 
left  eye  is  to  be  examined  ;  by  doing  this  his  pupil  remains  dilated 
and  there  is  no  effort  at  accommodation  if  the  stare  is  a  vacant 
one.  Then  the  physician  places  the  ophthalmoscope  before  his 
eye,  and  moves  it  about  somewhat  till  the  bright  beam  of  light 
strikes  the  patient's  pupil,  a  proceeding  that  often  enough  mis- 
carries with  the  inexperienced  observer,  who  fails  to  illuminate  even 
the  body,  let  alone  the  eye  of  the  patient.  The  pupil  appears 
bright  red,  and,  of  course,  contracts  somewhat  under  the  stimulus 
of  the  light.  This  contraction  is  insignificant,  because,  if  the  atti- 
tude above  mentioned  is  maintained,  the  light  does  not  strike  the 
most  sensitive  area  of  the  fundus,  the  macula  lutea,  but  falls  on  a 
portion  of  the  retina  which  is  less  apt  to  cause  a  reflex  pupillary 
reaction. 


Il8  OBJECTIVE    METHODS    OF    INVESTIGATION. 

(A)  TRANSILLUMINATION. 
If  a  foreign  body  or  an  opacity  is  present  in  the  pupillary  area, 
it  appears  as  a  dark  spot  on  a  red  ground.     If  this  opacity  is  not 
very  dense,  a  nebecula  corneae,  for  example,  it  appears  as  a  mere 
shadow  on  a  bright  ground. 

Any  spot  appearing  black  or  dark  by  transillumination  seems  white,  or  lighter  than 
its  surroundings  by  focal  illumination.  The  explanation  is  easy.  Opaque  spots  are  only 
partially  or  not  at  all  transparent ;  luminous  rays  proceeding  from  the  fundus  and  falling 
on  the  opacities  (from  behind)  are  returned  to  the  fundus  and  are  not  seen  by  the  obser- 
ver. The  reverse  is  true  of  focal  illumination ;  rays  reflected  from  opaque  spots  do  not 
reach  the  retina  of  the  patient,  but  are  thrown  into  the  eye  of  the  observer. 

In  locating  an  opacity  one  fact  must  always  be  remembered,  that 
spots  on  the  cornea  and  lens  are  immovable,  while  anything  in  the 


Fig.  49. — Localization  of  Opacities  in  Cornea  and  Lens. 

vitreous  is  generally  movable.  If  the  patient  be  asked  to  look  with 
jerky  movements  upward  and  downward,  to  the  right  and  left, 
these  unsettled  cloudinesses  of  the  vitreous  continue  to  float  within 
the  pupillary  area  after  the  eye  has  ceased  to  move,  till  they  slowly 
sink  out  of  sight  by  their  own  gravity.  They  may  have  the  shape 
of  threads,  clouds,  lumps,  or  misty  films. 

Opacities  of  the  cornea  have  no  movement  independent  of  the 
eyeball.  To  distinguish  them,  in  addition  to  focal  illumination 
(/.  g8)  we  use  the  phenomenon  of  parallactic  displacement.  Let 
the  point  a.  Fig.  ^g,  be  an  opacity  of  the  cornea,  the  point  b  an 
opacity  in  an  anterior  layer  of  the  lens  about  in  the  pupillary  plane, 


USE    OF   THE    OPHTHALMOSCOPE.  I  I9 

the  point  c  an  opacity  on  the  posterior  surface  of  the  lens.  Then 
the  observer,  looking  in  the  direction  of  the  optical  axis  into  the 
patient's  pupil,  sees  only  one  opacity,  as  is  illustrated  in  a,  Fig.  ^g. 
Now  ask  the  patient  to  look  downward ;  all  the  opacities  now 
become  visible,  the  corneal  opacity  lying  below,  the  posterior  lens 
opacity  above,  the  opacity  b  in  the  middle.  This  last,  apparently, 
has  not  changed  its  place;  the  posterior  one  seems  to  have  risen. 
(As  a  matter  of  fact,  they  have  all  three  descended  somewhat.)  An 
apparent  movement  in  a  direction  opposite  to  the  actual  movement 
of  the  patient's  eye  is  a  proof  that  any  opacity  lies  behind  the 
pupillary  plane ;  an  apparent  movement  in  the  actual  direction  of 
the  patient's  eye  indicates  a  position  in  front  of  the  pupillary  plane. 
If  the  patient's  eye  remains  still  and  the  observer  himself  moves, 
the  opposite  is  true ;  that  is,  opacities  lying  in  front  of  the  pupil 
seem  to  move  in  the  opposite  direction,  opacities  behind  the  pupil 
in  the  same  direction.  The  extent  of  this  apparent  movement 
gives  us  a  clue  to  determinfe  the  distance  of  the  opacity  either  in 
front  of  or  behind  the  pupillary  plane. 

The  examination  of  corneal  and  lens  opacities  by  transillumination  can  be  completed 
by  placing  behind  the  sight-hole  of  the  ophthalmoscope  a  convex  lens  which  allows  the 
observer  to  approach  closer  to  the  opacity,  and  which  magnifies  it  at  the  same  time. 
Hirschberg  and  Magnus  have  developed  this  method  and  devised  special  instruments 
for  it ;  the  strong  lenses  of  the  refraction  ophthalmoscope  can,  however,  be  used  for  the 
same  purpose. 

Transillumination  effects  more  than  focal  illumination  in  a  case, 
for  exainple,  where  an  attempt  is  made  to  discover  a  small  hole  in 
the  iris  through  which  a  splinter  of  iron  may  have  passed  into  the 
eye.  A  luxation  of  the  lens,  or  a  movable  lens,  can  best  and  easiest 
be  recognized  by  transillumination. 

(B)  EXAMINATION  OF  THE  FUNDUS  OF  THE  EYE. 
It  is  advisable  for  the  beginner  to  commence  with  the  examina- 
tion of  the  upright  image  of  an  atropinized  eye.  A  rabbit  is  a 
good  subject  for  experiment,  since  it  remains  still  if  placed  in  a 
suitable  receptacle,  has  hyperopic  eyes,  and  does  not  complain  of 
blindness  or  discomfort  at  long  seances.  Moreover,  its  fundus  has 
a  very  characteristic  structure,  whose  lines  and  colors  are  easily  de- 
scribed and  drawn.  The  first  effort  consists  of  obtaining  a  view 
of  the  optic  nerve  entrance  (papilla  nervi  optici).  The  observer, 
in  examining  a  rabbit's  eye,  looks  from  below  upward  and  back- 


I20  OBJECTIVE    METHODS    OF    INVESTIGATION. 

ward ;  he  knows  he  is  in  the  right  direction  when  he  sees  that  the 
usual  red  appearance  of  the  fundus  has  changed  to  a  white  shim- 
mer. To  be  sure,  the  medullary  fibers  also  return  a  white  reflex, 
but  much  has  been  accomplished  when  even  this  is  discovered. 
The  best  method  is  to  begin  at  a  distance  of  about  20  an.,  and  to 
throw  the  light  from  the  mirror  in  various  directions  on  to  the 
pupil  till  a  white  reflex  appears,  then  to  approach  as  close  as  pos- 
sible to  the  eye  under  examination.  If  this  effect  is  lost  by  inex- 
perience, begin  over  again  in  the  same  way,  till  the  eye  can  be  ap- 
proached very  closely  without  losing  this  white  reflex  from  the 
pupil.  The  next  is  the  hardest  task — to  find  the  proper  focal 
adjustment  for  the  location  of  the  virtual  image  of  the  fundus.  As 
the  observer  knows  that  the  object  he  is  examining  lies  just  in  front 
of  his  eye,  he  accommodates  instinctively  and  thereby  prevents 
the  most  accurate  vision;  he  must  therefore  try  to  imagine  that 
the  object  of  his  attention  lies  far  off,  or  in  case  this  does  not  suffice 
he  must  neutralize  his  accommodation  by  concave  lenses.  On 
account  of  this  instinctive  accommodation  the  beginner  is  often 
able  to  see  the  fundus  the  easier,  the  more  hyperopic  the  patient  is, 
that  is,  the  nearer  the  virtual  image  of  the  fundus  lies  to  the  actual 
fundus.  If  all  this  is  successful,  let  the  student  take  pencil  and 
paper  and  try  to  reproduce  what  he  sees  in  a  drawing,  even  if  it 
be  imperfect ;  this  sharpens  the  attention  decidedly  and  protects 
the  student  from  many  errors  to  which  he  might  otherwise  fall  a 
victim. 

If  the  first  difficulties  are  overcome  and  the  student  can  see  the 
upright  image,  the  papilla,  the  retinal  vessels,  and  the  medullary 
nerve  fibers  in  the  rabbit's  eye,  let  him  make  the  more  difficult 
attempt  to  see  the  inverted  image  of  the  fundus  {Fig.  40,  p.  loy). 
Let  us  suppose  that  this  attempt  is  made  on  man  ;  we  must  then  try 
to  see  the  optic  disc,  first,  because  this  spot  on  the  fundus  is  the 
brightest  and  the  easiest  to  describe,  second,  because  it  is  insensi- 
tive to  light,  its  illumination  neither  blinding  the  eye  nor  causing 
contraction  of  the  pupil.  On  page  6g  we  saw  that  the  papilla  in 
man  lies  about  12°  to  75°,  reckoned  from  the  nodal  point,  toward 
the  nasal  side  of  the  fovea  centralis.  We  must,  therefore,  after 
having  induced  the  patient  to  gaze  in  a  certain  direction,  look  into 
the  eye  at  that  angle  measured  from  tlie  visual  axis  outward  (toward 
the  temporal  side). 

The  observer  is  now  at  about  40  cm.  distance  from  the  patient, 


USE    OF   THE    OPHTHALMOSCOPE.  121 

and  he  illuminates  the  pupil  back  and  forth  until  it  appears  white, 
or  at  least  a  paler  red.  Then,  holding  the  convex  lens  between  his 
index  finger  and  thumb,  he  introduces  it  into  the  path  of  the  lumin- 
ous rays,  taking  care  that  the  left  hand  does  not  tremble  in  the  air 
but  is  supported  by  the  little  and  ring  fingers  resting  on  the 
patient's  forehead.  Generally  the  beginner  sees  nothing  at  the  first 
attempt  but  reflexes — images  of  the  mirror  reflected  from  the  con- 
vex lens  or  from  the  cornea,  but  by  tilting  the  lens  a  little  from  the 
optic  axis,  the  observer  learns  to  obliterate  from  his  visual  field 
these  disturbing  images.  It  should  not  be  forgotten,  however,  that 
if  the  lens  is  held  too  obliquely  the  fundus  may  be  astigmatically 
distorted,  and  therefore  the  lens  should  be  tilted  only  to  the  mini- 
mum extent  necessary.  If  light  has  not  been  by  this  means 
diverted  from  the  patient's  pupil,  the  last  and  hardest  step  comes 
now — for  the  observer  to  accommodate  for  the  image  in  the  air. 
Since  the  beginner  generally  has  the  impression  that  the  object  he 
is  looking  at  is  in  the  eye,  he  accommodates  for  that  distance ;  but 
the  aerial  image  for  which  he  should  accommodate  lies  in  front  of 
the  eye  and  in  front  of  the  convex  lens,  and,  therefore,  by  accom- 
modation for  the  actual  location  of  the  fundus  he  cannot  obtain  a 
perfect  view  of  the  image. 

To  learn  how  to  conquer  this  difficulty,  one  can  practise  reading  print  held  upside 
down  and  looked  at  through  a  convex  lens.  The  convex  lens  gives  an  inverted  image  of 
the  inverted  print,  that  is,  it  gives  an  upright  image  between  the  lens  and  the  reader,  and 
the  print  is  unreadable  so  long  as  the  observer  cannot  bring  about  the  adjustment  neces- 
sary for  the  location  of  the  aerial  image  between  his  eye  and  the  lens.  This  adjustment 
can  be  more  easily  acquired  by  holding  a  needle  at  about  the  spot  where  he  expects  the 
image  to  be.  If  he  cannot  find  this  aerial  image,  let  him  try  with  a  convex  lens  of  2 
or  J  diopters,  such  as  is  found  in  any  refraction  ophthalmoscope. 

After  the  disc  has  been  seen  and  an  opinion  formed  concerning 
its  normal  or  pathological  condition,  the  student  proceeds  to  exam- 
ine the  fundus  in  detail.  The  neighborhood  of  the  nerve  sheath 
and  the  spot  most  necessary  to  vision  (the  macula  lutea)  can  be 
brought  into  view  by  moving  the  convex  lens  ;  the  rays  emitted 
from  the  fundus  pass  in  that  case  through  the  periphery  of  the  lens, 
which  acts  as  a  prism  to  deflect  these  rays  toward  the  base,  and 
consequently  the  observer  does  not  see  that  portion  of  the  fundus 
which  lies  exactly  opposite  the  lens,  but  other  areas  lying  some- 
what to  the  side. 

To  view  the  fundus  at  a  still  greater  distance  from  the  disc,  the 
patient  changes  the  direction  of  his  ga^e,  or  the  physician  moves 


122  OBJECTIVE    METHODS    OF    INVESTIGATION. 

his  own  head  and  looks  at  the  fundus  from  above,  from  the  right 
and  from  the  left ;  but  the  upper  half  of  the  retina  can  be  seen  only 
when  the  patient  looks  upward. 

Although  the  various  pathological  changes  in  individual  diseases 
will  be  discussed  later,  this  is  the  best  place  to  introduce  a  short 
description  of  the  normal  fundus.  On  the  red  ground  is  seen  the 
lighter  papilla  with  the  retinal  vessels  arising  from  it.  As  to  the 
ground  itself,  its  color  changes  from  yellowish-red  to  reddish-brown 
according  as  the  individual  is  light  or  dark  haired.  Boll,  the  dis- 
coverer of  the  visual  purple,  ascribes  the  red  of  the  fundus  to  the 
presence  of  a  retinal  purple,  but  this  view  is  not  tenable.  Visual 
purple  is  a  quite  different  red  (rose,  blue-red,  hence  the  name  pur- 
ple) and  can  be  bleached  out  without  materially  changing  the  color 
of  the  fundus.  Undoubtedly  the  red  of  the  fundus  is  due  to  the 
blood  of  the  choroid.  The  capillaries  of  the  choroid  are  covered 
only  by  the  transparent  retina  and  the  translucent  but  not  trans- 
parent pigment-epithelium.  The  abundance  of  pigment  in  the  epi- 
thelium has,  consequently,  the  illumination  being  the  same,  the 
greatest  influence  on  the  color  of  the  fundus.  This  abundance  of 
pigment  directly  corresponds  also  to  the  pigmentation  in  other 
parts  of  the  body ;  in  the  negro  it  is  so  great  that  the  bloodredness 
of  the  choroid  can  scarcely  be  distinguished. 

The  papilla  nervi  optici  is  the  most  remarkable  spot  of  the  fundus, 
and  is  the  area  at  which  every  ophthalmoscopic  examination 
begins.  The  name  would  indicate  that  something  protrudes  above 
the  surface  of  the  fundus,  but  that  is  not  the  case.  Anatomically 
the  condition  is  as  follows  {Fig.  50) :  the  choroid  has  a  hole  in  it 
extending  through  the  sclera;  this  aperture  is  crossed  by  a  net- 
work of  fibers  from  the  scleral  tissue.  The  optic  nerve  fibers  have 
their  normal  medullary  sheath  as  far  as  this  network,  the  so-called 
lamina  cribrosa  {Fig.  50),  but  inside  this  network,  that  is,  within 
the  sclera,  the  medulla  is  lost.  After  the  naked  axis  cylinders  have 
passed  through  the  opening  in  the  choroid  they  bend  nearly  at 
right  angles  and  spread  out  as  the  innermost  retinal  layer  as  far  as 
the  periphery  of  the  fundus.  There  is,  therefore,  no  reason  for  call- 
ing it  a  prominence  (papilla). 

The  external  border  of  the  optic  nerve  sheath  {Fig.  5/)  is  a  black 
circular  line  called  the  choroidal  ring,  because  it  bounds  the  open- 
ing in  the  choroid  through  which  the  optic  nerve  enters  into  the 
eyeball.     Next  the  choroidal  ring  inward  is  the  scleral  ring  {Figs. 


USE    OF   THE   OPHTHALMOSCOPE. 


123 


50  and  5/),  and  the  hole  in  the  choroid  being  greater  than  that  in 
the  sclera,  the  latter  is  therefore  visible.     The  choroidal  and  scleral 


OfiticTierve. 


Fig.  50. — Section  through  Optic  Nerve  and  Papilla.     {After  Fleinming^ 


Branches  of  the 

Vena  nasalis 

inferior. 


Branchesofthe 

Vena  nasalis 

superior. 


Fig.  51. — The  Normal  Fundus  in  the  Inverted  Image.     {After  Jaeger  ) 
The  choroidal  ring  can  be  distinguished  along  the  whole  circumference,  the  scleral  ring  only  on  the  right 

side. 


rings  are,  of  course,  not  so  exact  as  circles  drawn  by  a  compass  ;  in 
fact,  the  deviation  from  the  circular  form  is  so  noticeable  that  the 


124  OBJECTIVE    METHODS    OF    INVESTIGATION. 

optic  nerve  sheath  ought  rather  to  be  called  egg-shaped.  This 
may  be  the  result  of  astigmatism  (/.  128)  or  of  an  anatomical 
peculiarity  of  the  sheath.  In  many  eyes  no  exact  rings  can  be 
found  at  all,  or  the  choroidal  ring  is  present  only  as  small  collec- 
tions of  pigment  at  intervals. 

The  real  nerve  sheath,  thus  bounded  by  two  rings,  is  on  its  nasal 
half  less  sharply  bordered  and  has  a  darker  color ;  while  on  the  tem- 
poral and  larger  half  the  color  is  lighter  and  the  border  more  distinct. 
In  the  middle  of  the  sheath  is  a  lighter  spot,  the  funnel-shaped 
depression,  from  the  nasal  side  of  which  spring  the  arteria  and  vena 
centralis  retinae.  This  excavation  sometimes  extends  over  to  the 
temporal  side  of  the  sheath  and  is  therefore  called  the  physiological 
cup  {Figs.  143  and  145). 

The  arteria  and  vena  centralis  retifice  while  yet  within  the  cup  are 
each  divided  into  an  ascending  and  a  descending  branch  {Fig.  ji) ; 
each  of  these  branches  again,  either  within  the  sheath  or  just  out- 
side of  it,  divides  into  nasal  and  temporal  branches  which  spread  out, 
tree-like,  into  the  smallest  twigs.  Hence  we  distinguish  an  arteria 
nasalis  stiperior  and  inferior,  temporalis  superior  and  inferior,  the 
veins  being  the  same.  The  arteries  are  known  by  their  smaller 
caliber,  their  more  extended  course,  their  brighter  color,  and  the 
so-called  reflex — a  bright  line  in  the  middle  of  the  vessel.  The 
veins  are  known  by  their  greater  thickness,  more  tortuous  course, 
darker  red,  smaller  and  less  bright  central  streaks  (they  may  be 
entirely  absent).  The  reflexes  are  clearly  seen,  however,  only  in 
the  examination  of  the  upright  image. 

The  nature  of  the  reflexes  is  still  a  disputed  point.  One  authority  explains  them  as 
reflex  from  the  vessel  wall,  another  as  from  the  blood  column.  Dimmer,  who  has  lately 
taken  up  the  subject  anew,  ascribes  the  narrow  reflex  of  the  veins  to  the  play  of  light  on 
the  surface  of  the  blood  column,  and  the  broad  reflex  of  the  arteries  to  that  on  the  "  axis 
stream" — that  is,  to  the  rebound  of  light  from  the  blood  corpuscles  flowing  rapidly  in 
the  channel  of  the  vascular  tube. 

Only  small  vessels  appear  on  the  temporal  and  nasal  side  of  the 
nerve  sheath.  These  should  be  used  in  making  the  examination 
of  the  upright  image  (the  direct  method)  as  a  test  object  for  the 
proper  refraction.  About  one  and  a  half  to  two  times  the  width  of 
the  nerve  sheath  toward  the  temporal  side  is  an  area  in  which 
there  are  no  blood-vessels,  or  at  least  none  visible  to  the  ophthal- 
moscope. This  is  called  the  yellow  spot,  macula  lutea,  with  the 
fovea  centralis,  the  area  of  most  distinct  vision.    It  varies  in  appear- 


USE   OF   THE    OPHTHALMOSCOPE.  12$ 

ance  according  as  it  is  viewed  in  the  upright  or  in  the  inverted 
image.  In  the  upright  image  it  appears  about  the  size  of  the  disc, 
distinguishable  from  the  surrounding  fundus  by  being  somewhat 
darker  in  color ;  in  the  middle  of  it  is  a  sickle  or  fan-shaped  or 
rounded  point  of  light.  In  the  inverted  image  {Fig.  ji)  the  yellow- 
spot  in  young  persons  appears  to  be  bordered  by  a  line  describing 
an  egg-shaped  figure  with  its  long  axis  horizontal. 

These  phenomena  can  be  thus  explained :  The  light  thrown  on  the  fundus  is  partly 
returned  as  diflFused,  that  is,  each  point  of  the  fundus  returns  luminous  rays  diverging  in 
all  directions  ;  each  point,  therefore,  is  luminous.  Some  of  these  rays  reach  the  observer's 
eye  and  enable  him  to  see  vessels,  pigment  spots,  differences  of  level,  etc.  But  on  the 
inner  surface  of  the  retina  there  are  regularly  cuned  areas  that  act  as  concave  or  convex 
or  cylindrical  mirrors  according  to  their  curvature,  and  consequently  rays  proceeding 
from  the  ophthalmoscope  are  returned  to  form  small  reflected  images — actual  if  in  front 
of  the  retina,  virtual  if  behind  it.  These  images  of  the  ophthalmoscope  are  seen  by  the 
observer  only  when  a  narrow  cone  of  light  from  an  image  reaches  his  eye. 

The  fact  that  the  yellow  spot,  round  anatomically,  appears  egg-shaped  to  the  observer 
is  explained  by  Johnson  to  be  a  distortion  caused  by  the  mirror  and  convex  lens. 

There  are  other  differences  besides  those  given  here,  and  the 
beginner  is  apt  to  call  them  pathological,  although  they  are  only 
modifications  of  a  healthy  fundus.  One  of  the  most  common  is  the 
visibility  of  the  choroidal  vessels ;  they  may  be  distinguished  from 
the  retinal  vessels  by  their  ribbon-like  appearance,  their  arrange- 
ment in  parallel  groups,  and  their  lack  of  branches.  Again,  the 
pigmentation  may  not  be  regular,  so  that  the  fundus  loses  its  uni- 
form appearance  and  seems  parceled  off"  into  divisions.  One  sees 
dark  spots  with  bright  red  streaks  between  ;  the  streaks  are  chor- 
oidal vessels,  the  dark  spots  are  the  "  intervascular  spaces." 
Finally  must  be  mentioned  the  reflexes  along  the  vessels,  giving  to 
the  retina  a  peculiar  glittering  appearance,  but  easily  distinguish- 
able from  retinal  opacities,  which  are  constant  and  immovable,  by 
the  fact  that  the  reflexes  seem  to  be  moved  and  displaced  when  the 
mirror  is  turned. 

(C)  ESTIMATION  OF  REFRACTIVE  CONDITIONS. 
Even  when  illuminating  the  refractive  media  {p.  ii8  et  seq^,  we 
may  often  determine  whether  the  patient  is  hyperopic  or  myopic. 
In  many  cases  retinal  vessels  are  visible  at  quite  an  appreciable 
distance ;  if  now  we  find  an  actual,  inv^erted  aerial  image  in  front  of 
the  patient's  eye,  the  condition  must  be  myopia;  if,  on  the  other 
hand,  the  image  is  virtual,  upright,  and  behind  the  patient's  eye,  the 


126  OBJECTIVE    METHODS    OF    INVESTIGATION, 

condition  must  be  hyperopia.  It  is  easy  to  decide  which  of  the 
two  is  the  case.  Let  the  observer  move  his  own  head  toward  his 
right ;  if  he  sees  the  vessels,  and  if  they  make  an  apparent  movement 
toward  the  left,  that  is,  in  an  opposite  direction,  they  belong  to  an 
image  of  the  fundus  inverted  and  in  front  of  the  pupil,  and  the  eye 
is  myopic.  If,  however,  the  vessels  appear  to  move  with  the 
observer's  head,  they  belong  to  an  image  which  is  upright  and 
behind  the  pupil,  and  the  eye  is  hyperopic.  In  emmetropia  or  any 
trifling  degree  of  myopia  and  hyperopia,  the  vessels  of  the  patient's 
eye  are  not  visible  at  the  usual  distance  because  the  ophthalmo- 
scopic field  is  too  small  {p.  log). 

To  understand  the  principles  of  these  apparent  movements  it  must  be  remembered  that 
these  images  of  the  fundus  are  projected  by  the  observer  toward  the  pupil  of  the  patient, 
whose  eye  therefore  seems  to  be  at  rest  while  the  images  of  the  fundus  seem  to  move. 
That  the  movement  appears  to  go  with  the  observer's  head  when  the  image  is  upright, 
against  it  when  the  image  is  inverted,  we  can  understand  when  we  turn  to  the  explana- 
tions of  the  apparent  displacement  of  corneal  opacities  in  front  of  the  pupillary  plane, 
and  of  lens  opacities  behind  the  pupillary  plane  (/.  ii8^.  The  point  a  {Fig.  ^g)  corre- 
sponds to  the  inverted  image,  the  point  c  to  the  upright  image. 

Obviously,  it  does  not  suflfice  to  have  determined  whether  the 
patient's  far  point  lies  close  in  front  of  his  eye  (strong  myopia)  or 
close  behind  it  (strong  hyperopia),  or  at  some  distance  from  his  eye 
(moderate  myopia,  moderate  hyperopia,  or  emmetropia) ;  our  task 
is  rather  to  measure  the  refractive  condition.  This  can  be  carried 
out  in  three  ways,  namely  : — 

(a)  by  the  upright  image  (the  direct  method) ; 

(/?)  by  the  inverted  image  (the  indirect  method) ; 

iy)  by  skiascopy  (the  shadow  test). 

(a)  The  estimation  of  the  refraction  by  the  upright  image  is  carried 
out  by  means  of  the  refraction  ophthalmoscope  {Fig.  48).  The 
emmetropic  observer  first  tries  to  see  the  papilla  without  any  lens 
at  all ;  if  he  is  not  successful  he  introduces  successively  behind  the 
sight  hole  of  the  mirror  by  revolving  the  disk  a  series  of  concave 
or  convex  lenses  until  he  finds  the  lens  with  which  he  can  see  the 
patient's  fundus  most  clearly.  This  lens  measures  the  amount  of 
refractive  error  present,  assuming  that  neither  the  observer  nor  the 
patient  makes  an  effort  at  accommodation,  and  taking  care  that  the 
distance  of  the  lens  from  the  patient's  eye  is  negligibly  small — a 
condition  admissible  only  in  errors  of  low  degree.  In  errors  of 
high  degree  a  distance  of  the  neutralizing  lens  from  the  patient's 
eye  of  five  or  more  centimeters   is  of  considerable  importance, 


USE    OF    THE   OPHTHALMOSCOPE. 


127 


since  without  taking  this  distance  into  consideration  myopia  might 
be  found  too  great  and  hyperopia  too  small. 

Let  us  take  an  example.  In  Fig.  §2,  Pa  is  the  patient's  eye,  and  has  a  myopia  of 
10. o  D ;  therefore  luminous  rays  emitted  from  the  fundus  of  Pa  will  produce  an  inverted, 
enlarged  image,  a'  b' ,  at  y'^  in.  =  10  an.  in  front  of  the  principal  plane.  Let  the  eye,  Ob, 
be  J  cm.  from  Pa  ;  supposing  this  observer's  eye  to  be  emmetropic  and  free  from  accom- 
modation, it  will  see  distinctly  the  fundus  of  Pa  when  using  a  concave  lens  which  makes 
parallel  the  rays  converging  to  b' ,  in  other  words,  a  lens  whose  (negative)  focus  is  equal 
to  the  distance  between  L  L  and  a'  b' .  If  this  concave  lens  is  at  /  cm.  in  front  of  the 
principal  plane  of  Ob,  that  is,  4  cm.  in  front  of  the  principal  plane  of  Pa,  then  the  focal 

distance  of  the  lens  would  have  to  be  6  cm.  and  its  refractive  power    — ; '-  =   16.66 — 

■^  6  cm. 

Diopters;  the  neutralizing  lens  is  therefore  6.66 —  D  stronger  than  the  myopia  of  Pa. 

A  corresjx)nding  example  shows  that  an  emmetropic  observer  free  from  accommoda- 
tion sees  distinctly  the  fundus  of  an  eye  of  10. o  D  hyperopia  at  a  distance  of  j  cm.  with 
a  convex  lens  of  y.iD  placed  /  cm.  in  front  of  the  principal  plane  of  Ob,  that  is,  4  cm. 
in  front  of  the  principal  plane  of  Pa.     The  error  is  consequently  2.g  Diopters. 

Such  palpable  errors  ought  not  to  be  made.     If  they  cannot  be  avoided  they  can  at 


^^-iii**""^ 


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Fig.  52. — Effect  of  the   Distance   Between   Patient  and  Observer,  in  the   Estimation  of 
Refraction  by  the  UPRifiHT  Image. 


least  be  modified  if  the  neutralizing  lens  is  placed  close  to  the  patient's  eye,  rather  than 
close  to  the  observer's  own.  Supposing  in  the  above  example  of  myopia  of  70.0  D  the 
neutralizing  lens  is  placed  /  cm.  in  front  of  the  principal  plane  of  Pa,  the  lens  should 
then  have  a  focal  distance  of  g  cm.,  a  refractive  power  of  i i.ii —  Diopters,  in  order  to 
give  to  the  emmetropic  observer  Ob  a  distinct  view  of  the  fundus  of  Pa.  The  error 
in  this  case  is  only  /.// — Diopters.  Since  one  must  thus  sacrifice  the  very  advantages 
peculiar  to  the  refraction  ophthalmoscope,  it  is  best,  therefore,  in  cases  of  high  degree  of 
ametropia,  to  use  another  method,  the  shadow  test,  which,  even  at  the  worst,  makes  an 
error  of  only  about  i .0  Diopter. 

If  the  observer  himself  has  any  refractive  error,  he  must  either 
correct  it  with  a  suitable  lens  during  the  examination,  or  make 
allowance  for  this  error  when  estimating  the  patient's  condition. 
In  any  case  he  must  take  the  refractive  condition  of  his  own  eye 
into  account. 

Suppose  the  observer  is  hyperopic  3.0  D  and  finds  that  — 2.0  D  gives  him  the  best 
view  of  the  patient's  fundus  (the  lens  being  at  a  negligible  distance  from  the  patient's 
eye).  The  patient  must  then  have  a  myopia  of  ( — 2.0  D)  -\-  ( — 3.0  D),  that  is,  of 
5.0  D ;  for  in  this  case  luminous  rays  emerging  from  the  patient's  cornea  are  not  made 
parallel,  but  are  only  weakened  enough  in  their  convergence  to  intersect  each  other  at  the 


128  OBJECTIVE    METHODS    OF    INVESTIGATION, 

(negative)  far  point  of  the  hyperopic  observer,  that  is,  ^  m. ,  JJ.J  cm.  behind  the  principal 
plane  of  Oh.  It  would  require  a  concave  lens  strong  enough  to  overcome  this  converg- 
ence, than  is,  the  lens  already  found  plus  a  second  lens  of  — j.o  D,  before  the  rays 
could  be  made  parallel ;  this  lens  is  therefore  the  real  measure  of  the  myopia. 

Or  suppose  the  observer  with  myopia  of  j.o  D  sees  the  fundus  of  the  patient's  eye 
with — 2.0  D  ;  then  the  patient  has  obviously  3.0  D  — 2.0  D  =  i.o  D  of  hyperopia ;  for 
a  myopic  oliserver  of  j.o  D,  with  lenses  of  — 2.0  D  is  changed  to  a  myope  of  i.o  D. 
He  now  sees  (without  accommodation)  everything  lying  at  i  in.  in  front  of  him.  The 
virtual  image  of  the  fundus  must  therefore  have  lain  i  m.  in  front  of  the  observer  (the 
distance  between  the  two  being  neglected)  or  7  ;;/.  behind  the  patient.  An  eye  with 
negative  far  point  of  /  vi.  is  hyperopic  to  the  extent  of  i.o  D. 

A  general  ride  may  be  thus  expressed :  If  the  patient's  refractive 
condition  is  of  a  character  opposite  to  that  of  the  ante  tropic  observer, 
the  tatter's  refractive  error  expressed  in  diopters  is  added  to  that  lens 
tvhich  neutralises  the  error  f 01  Did.  If  the  patient' s  refractive  condition 
is  of  the  same  character  as  that  of  the  ametropic  observer,  the  latter  s 
refractive  error  expressed  in  diopters  is  subtracted  from  that  lens  zvhich 
neutralizes  the  error  found.  Suppose  the  observer  is  hyperopic,  and 
that,  without  correcting  his  own  ametropia,  he  finds  the  patient  to 
be  myopic ;  the  myopia  thus  found  must  be  increased  by  the 
amount  of  the  observer's  hyperopia.  Or,  suppose  the  observer  is 
hyperopic,  and  without  correcting  his  own  hyperopia  finds  the 
patient  also  hyperopic  ;  the  observer  then  subtracts  his  own  hyper- 
opia from  that  of  the  patient.     And  so  forth. 

If  there  is  astigmatism,  the  proper  correction  for  both  principal 
meridians  cannot  be  made  at  the  same  time  with  spherical  lenses. 
The  retinal  vessels  parallel  to  one  principal  meridian  are  sharp, 
those  perpendicular  to  it  are  hazy.  The  astigmatism  might  now 
be  measured  by  selecting  the  lens  correcting  the  error  in  one  prin- 
cipal meridian,  and  then  the  lens  correcting  the  error  in  the  other 
principal  meridian :  the  difference  between  these  lenses  would  be 
the  measure  of  the  astigmatism  present.  The  lens  with  which  one 
sees  distinctly  horizontal  retinal  vessels  measures  the  defect  of  the 
perpendicular  meridian.  But,  unfortunately,  retinal  vessels  are  not 
always  so  obliging  as  to  run  exactly  parallel  to  the  principal  meri- 
dians ;  therefore  we  may  try  to  neutralize  the  astigmatism  by 
means  of  cylindrical  lenses.  If  we  succeed  and  the  proper  correc- 
tion is  obtained,  the  retinal  vessels  of  both  principal  meridians 
must  obviously  be  seen  with  the  same  distinctness. 

This  method  is  warmly  recommended  by  Parent.  Ophthalmoscopes  provided  with 
cylindrical  lenses  are,  however,  very  expensive,  and  the  decision  as  to  which  is  the  neu- 
tralizing lens  cannot  always  be  depended  on.     Besides,  it  is  most  important  to  remember 


USE    OF   THE   OPHTHALMOSCOPE,  1 29 

that  the  distance  of  the  lens  from  the  principal  plane  of  the  patient's  eye  will  be  a  source 
of  still  greater  error  than  that  found  in  the  measurement  by  means  of  spherical  lenses. 
In  any  case  we  possess  in  the  shadow-test  a  method  which  is  much  cheaper  and  more 
easily  applied  than  that  just  mentioned. 

It  is  advisable  to  combine  the  examination  of  the  upright  with 
that  of  the  inverted  image  (Schweigger's  method).  Any  astigma- 
tism, even  if  it  cannot  be  measured,  can  be  detected  thereby  with 
great  speed  and  confidence  if  it  is  not  too  small.  The  method  is 
as  follows :  If  the  optic  nerve  sheath  of  the  patient's  eye  is  anatom- 
ically round,  it  appears,  if  the  eye  is  astiginatic,  to  be  an  ellipse — 
an  ellipse  placed  perpendicularly  if  the  perpendicular  meridian  has 
the  stronger  curvature,  and  an  ellipse  placed  horizontally  if,  as 
is  seldom  the  case,  the  horizontal  meridian  has  the  stronger 
curvature.^ 

If  now  we  use  a  convex  lens  ^  to  examine  an  astigmatic  eye  in 
the  inverted  image,  the  diameter  of  the  image  of  the  disc  must 
appear  shorter  in  its  perpendicular  principal  meridian,  because  the 
refraction  in  this  meridian  is  greater  (/.  log).  The  disc  conse- 
quently appears  to  be  a  horizontal  ellipse  in  the  inverted  image. 
The  conclusion  is  unavoidable  that  there  must  be  astigmatism  if 
the  shape  of  the  disc  is  different  in  the  upright  image  from  that  in 
the  inverted.  Any  small  departure  in  the  shape  of  the  disc  from 
the  circular  form  in  only  one  method  of  examination  does  not 
warrant  the  diagnosis  of  astigmatism,  because  the  disc  anatomically 
is  as  often  egg-shaped  as  round. 

(,3)  Estimation  of  the  refraction  by  the  inverted  image  (indirect  method).  This 
method,  developed  and  particularly  recommended  by  Schmidt- Rimpler,  depends  upon  the 
following  fact :  An  image,  FF  (of  the  flame,  Fl),  reflected  from  a  concave  mirror,  Sp  {Fig- 
jj),  will  be  imaged  distinctly  on  the  fundus  of  an  eye  only  when  the  location  of  the 
image,  /7^,and  the  fundus  of  the  patient's  eye  are  conjugate  foci;  in  other  words,  when 

1  If  this  is  not  at  once  clear,  let  the  student  read  the  section  on  "  Magnification  of 
the  Upright  Image  "  (/.  /oy  et  seq.).  If  even  this  fails  to  make  it  clear  and  intelligible, 
the  student  may  make  use  of  an  experiment  to  convince  himself  of  the  practical  correct- 
ness of  the  statement,  at  least.  For  this  purpose,  let  him  take  from  the  case  of  test 
lenses  a  convex  spherical  and  a  convex  cylindrical  lens  of  about  -\-6.o  D  and  -^-4.0  Dc 
respectively.  He  then  puts  the  two  together,  one  over  the  other,  and  looks  through  this 
meridian-asymmetric  system  at  the  optic  nerve  sheath  in  Fig.  ji.  He  will  then  notice 
that  the  optic  nerve  sheath,  actually  round,  now  appears  elliptical,  the  long  axis  of  the 
ellipse  being  perpendicular  to  the  axis  of  the  cylinder ;  in  other  words,  the  long  axis  of 
the  ellipse  lies  in  the  same  plane  as  the  meridian  of  strongest  curvature  in  the  meridian- 
asymmetric  system. 

*  The  lens  must  be  placed  so  close  to  the  eye  that  the  anterior  principal  plane  lies 
within  the  focal  length  of  the  lens. 
9 


130  OBJECTIVE    METHODS    OF    INVESTIGATION. 

the  far  point  of  Pa,  made  artificially  myopic  by  a  convex  lens,  .S'.S",  coincides  with  Fl' .  If 
now  the  refractive  power  of  ^S'.S'  and  its  distance  from  the  principal  plane  of  Pa  are  kept 
permanently  the  same,  then  the  spot  where  FF  should  be  thrown  in  order  to  produce  in 
Pa  a  distinct  Fl"  depends  only  upon  the  refractive  condition  of  Pa.  If  we  know  the 
location  oi  Fl',  we  can  determine  by  its  distance  from  ^5  the  refractive  condition  of  Pa. 

To  simplify  this  determination,  Schmidt- Rimpler  uses  a  convex  lens  of  10. o  D  placed 
10  cm.  in  front  of  the  principal  plane  of  Pa.  If  the  patient  is  emmetropic,  Fl'  must  lie 
at  the  focus  of  the  lens,  10  cm.  in  front  of  it,  in  order  to  produce  a  clear  image  in  Pa. 
If  Pa  is  myopic,  Fl'  must  lie  within  the  focal  distance  of  the  lens ;  and  if  Pa  is  hyperopia, 
Fl'  must  lie  beyond  this  focal  distance;  every  centimeter  toward  the  lens  indicating 
i.o  D  of  myopia  in  Pa,  and  every  centimeter  from  the  lens  indicating  i.o  D  ol  hyperopia 
in  Pa. 

In  the  practical  application  of  this  method  the  obser\'er  must 

(i)  Estimate  at  what  distance  his  mirror  must  be  placed  in  order  to  reproduce  a  clear 
image,  Fl" ,  on  the  fundus  of  Pa,  and 

(2)  Measure  where  the  image,  Fl' ,  lies  at  the  instant  that  Fl"  is  most  distinct. 

The  first  problem  can  be  solved  only  by  an  observer  whose  eye  is  corrected  for  the 


J>a.JE. 

Fig.  53. — Schmidt-Rimplbr's  Method  for  Measuring  Refraction. 

location  of  Fl' .  The  image,  Fl" ,  has  itself  become  an  object,  and  therefore  reproduces 
an  enlarged,  inverted  image,  Fl"' ,  exactly  upon  Fl' ,  and — neglecting  the  intensity  of  the 
illumination — coincides  with  it  point  for  point.  Although  the  observer  cannot  see  Fl' 
because  the  luminous  rays  proceed  from  him,  he  is  able  to  see  the  coincident  image,  Fl'", 
in  case  he  is  dioptrically  corrected  for  the  location  of  it. 

The  second  problem,  to  find  out  where  Fl'  (or  rather  Fl'")  lies,  is  solved  in  two 
steps :  (i)  by  measuring  the  distance  of  the  mirror,  Sp,  from  the  lens,  S  S,  at  the  instant 
that  Fl"  is  seen  distinctly ;  and  (2)  while  the  distance  of  the  flame,  Fl,  remains  unchanged, 
by  throwing  the  image,  Fl' ,  on  a  screen  and  then  measuring  how  far  the  screen  must  be 
removed  from  the  mirror  in  order  to  make  Fl'  perfectly  distinct.  The  difference  between 
these  two  distances  is  the  desired  distance  of  Fl'  and  Fl'"  from  S  S,  and  gives  at  once 
the  refractive  condition  sought. 

As  is  seen,  this  method  is  extremely  ingenious,  but  not  so  very  simple.  According  to 
Schmidt-Rimpler's  experience,  it  may  be  learned  by  any  one  who  can  use  the  ophthalmo- 
scope and  who  possesses  good  accommodative  power,  and  it  gives  as  good  results  as  does 
the  examination  of  the  upright  image,  that  is,  to  within  j .0  D  of  error.  He  advises  a 
small  and  handy  instrument  (refractometer) ,  with  which  the  fixation  of  S  S  2X  10  cm.  in 
front  of  the  principal  plane  of  the  patient's  eye,  as  well  as  the  measurement  of  the  dis- 


USE   OF   THE   OPHTHALMOSCOPE. 


131 


tance  of  the  mirror  from  S S,  is  easily  determined;  also,  instead  of  the  ordinary  gas 
flame,  he  advises  the  use  of  some  other  luminous  object  whose  image  admits  of  the 
recognition  of  the  smallest  errors  of  accommodation. 

(r)  Estimation  of  the  refraction  by  the  Shadozv  test.     Skiascopy. 

When  an  observer,  Ob  {Fig.  5^,  A,  B^  C),  sits  opposite  a  patient, 
Pa,  and  looks  at  the  pupil,  Pp,  of  Pa  with  proper  correction,  there  is 
formed  on  the  observer's  retina  a  reduced  and  inverted  image,  P'p'. 
All  luminous  rays  proceeding  from  the  fundus  of  Pa  through  the 
pupil,  p  P,  either  do  not  reach  the  eye  of  Ob  at  all,  or  they  strike  the 


Fig.  54. — Estimation  op  the  Refractive  Condition  by  Skiascopy. 


fundus  of  Ob  between  P'  and/'.  For  example,  all  rays  from  the 
point,  p,  irrespective  of  whether  they  come  from  one  point  or  from 
several  points  of  the  fundus  of  Pa,  must  unite  at  p'  of  Ob,  assuming, 
of  course,  that  they  are  intercepted  by  the  pupil  of  Ob.  Let  there 
be  a  luminous  point,  a,  on  the  fundus  {Fig.  j^.  A)  of  Pa,  and  let  Pa 
be  myopic ;  then  at  the  far  point  of  Pa  and  on  the  connecting  line  be- 
tween a  and  the  nodal  point  there  will  be  an  aerial  image,  a'.  The 
rays  diverging  from  a'  will  in  part  reach  the  pupil  of  Ob  beyond 
this  a',  and  in  passing  through  the  refractive  media  will  be  so  united 


132  OBJECTIVE    METHODS    OF    INVESTIGATION. 

that  the  image,  a' ' ,  would  result  if  the  rays  were  not  intercepted  by 
the  fundus  of  Ob.  On  the  upper  part  of  P p'  there  is  a  bright  dif- 
fusion circle,  while  the  lower  part  of  P* p'  remains  unilluminated. 
Now,  since  our  retinal  images  are  projected  into  the  outer  world  as 
inverted,  Ob  must  therefore  see  the  pupil  of  Pa  bright  below  and 
dark  above.  If  the  luminous  point,  a,  in  Pa  descends,  say  to  b,  its 
aerial  image  must  ascend  to  b',  and  there  results  a  bright  spot 
below  in  P p'  of  Ob  ;  consequently  the  observer  sees  in  the  pupil 
of  Pa  a  bright  area  passing  from  below  upward  t,  when  the  lu- 
minous point  in  the  fundus  oi  Pa  passes  from  above  downward  f. 

The  condition  is  exactly  the  reverse  \{-0b  is  within  the  far  point 
oi  Pa  {Fig.  5^,  B).  It  is  seen  that  a  would  produce  its  image  at  a' , 
but  on  account  of  the  refractive  media  of  Ob  this  image  is  really  at 
a' ',  that  is,  in  front  of  the  retina,  because  the  observer  is  corrected 
for  rays  diverging  from  //'while  receiving  convergent  rays.  The 
object  point,  a,  produces  therefore  in  this  case  a  diffusion  circle 
below  at  P p' ,  and  the  result  is  that  Ob  sees  the  pupil  o{  Pa  bright 
above  and  shaded  below.  If  the  object,  a,  in  Pa  passes  downward, 
say  to  b,  a' '  passes  upward  to  b' ';  consequently  the  observer  sees 
in  the  pupil  of  Pa  a  bright  area  passing  from  above  downward  in 
the  same  direction  as  the  luminous  point  in  Pa. 

And,  thirdly,  let  the  pupillary  plane  of  Ob  lie  exactly  at  the  far  point 
of  Pa  {Fig.  ^4.,  C) ;  then  the  object  point,  a,  produces  its  image,  a\ 
exactly  in  the  pupil  of  Ob.  Since  the  ray,  pa',  is  refracted  to  p'  and 
the  ray  Pa  is  refracted  to  P,  the  entire  area,  /'  P,  is  illuminated, 
and  consequently  the  entire  pupil  of  Pa  appears  luminous  to  Ob. 
Movement  of  the  object  point,  a,  to  b  in  this  case  has  no  effect ;  the 
entire  area,  /'  P ,  remains  luminous,  and  consequently  the  entire 
pupil,  Pp,  is  bright.  Not  until  a  passes  downward  still  further 
than  b  does  the  image,  b',  lie  on  the  iris  of  Ob,  in  which  condition 
no  luminous  ray  whatever  can  reach  p'  P,  and  at  one  stroke  the 
whole  pupil,  Pp,  becomes  dark. 

If  we  apply  what  has  been  said  for  one  object  point,  a,  of  Pa  to 
the  whole  field  of  light,  we  obtain  the  following  rule  for  the  shadow 
test :  If  an  observer  looks  at  the  pupil  of  a  patient  from  a  greater 
distance  than  that  of  the  patient's  far  point,  and  if  the  luminous 
area  in  the  fundus  of  the  patient's  eye  passes  downward,  the 
observer  sees  in  the  patient's  pupil  aluminous  area  passing  upward, 
that  is,  in  the  opposite  direction  to  that  actually  taken  by  the  lumi- 
nous area.     If,  however,  the  observer  is  within  the  patient's  far 


USE   OF  THE   OPHTHALMOSCOPE.  1 33 

point,  then  he  will  see  in  the  patient's  pupil  a  luminous  area  passing 
in  the  same  direction  as  the  actual  movement  of  the  luminous  area 
in  the  fundus.  Finally,  if  the  pupillary  plane  of  the  observer's  eye 
lies  at  the  patient's  far  point,  then  the  observer  sees  no  movement 
at  all,  but  a  sudden  illumination  of  the  patient's  entire  pupil  followed 
by  an  equally  sudden  shadow. 

In  this  we  have,  then,  a  method  of  finding  the  far  point  of  any 
eye  (free  from  accommodation)  by  approaching  or  withdrawing  our 
own  eye  to  or  from  the  patient's  eye,  until  the  movement  of  the 
light  and  shadow  in  the  same  direction  with,  or  in  the  opposite 
direction  to,  the  movement  of  the  luminous  field  ceases,  and  is 
replaced  by  an  instantaneous  change  from  total  light  to  total  dark- 
ness. 

In  order  to  apply  this  method  generally  in  all  refractive  condi- 
tions, we  must,  first,  be  able  to  establish  a  common  far  point  at 
about  JO  to  /f.o  cm.  This  is  made  possible  by  means  of  the  lenses 
of  the  oculist's  test  case.  Hyperopia  we  change  into  myopia, 
strong  myopia  we  change  into  moderate  myopia,  by  concave  glasses. 
We  must,  second,  be  able  to  obtain  a  play  of  light  in  definite  direc- 
tions upon  the  fundus  of  the  patient's  eye.  This  is  made  possible 
by  means  of  a  lamp  and  sl  plane  mirror.  The  plane  mirror  gives  a 
virtual,  upright  image  of  a  flame  lying  behind  the  observer;  this 
upright  image  becomes  an  inverted  image  in  the  patient's  eye. 
Consequently  a  downward  movement  of  the  mirror  image  effects  an 
upward  movement  of  the  luminous  area  in  Pa  {Fig.  ^^).  If  the 
mirror  is  turned  upward,  the  virtual  image  behind  the  mirror  moves 
downward,  while  the  illuminated  area  in /*<«  moves  upward,  a  move- 
ment in  the  same  direction  with  the  movement  of  the  mirror. 

If  a  concave  instead  of  a  plane  mirror  is  used  the  conditions  are  reversed  ;  that  is,  if 
the  mirror  is  rotated  upward,  the  luminous  area  on  the  patient's  retina  moves  downward. 

In  putting  the  shadow  test  into  practice  the  physician  sits 
opposite  the  patient  at  about  50  cm.  distance,  and  asks  hiin  to  look 
toward  a  remote  object  on  the  nasal  side  of  the  eye  to  be  tested. 
Then  with  the  plane  mirror  light  is  reflected  into  the  eye,  and  a  few 
movements  are  given  to  the  mirror  to  decide  whether  it  is  within 
or  without  the  far  point.  This  is  literally  the  work  of  a  flash !  If 
the  pupil  is  partly  dark  and  partly  bright,  it  is  a  proof  that  the 
pupillary  plane  of  the  observer  does  not  lie  at  the  far  point  of  the 
patient.  A  movement  of  the  visual  area  in  the  same  direction  as 
the  mirror   indicates  that  the  far  point  is  behind  the  observer ;  if 


134  OBJECTIVE    METHODS    OF    INVESTIGATION. 

against  the  direction  of  the  mirror,  the  far  point  lies  in  front  of  the 
observer.  In  the  last  case  the  observer  approaches  closer,  rotating 
the  mirror  occasionally,  until  the  light  and  shadow  do  not  seem  to 
pass  across  the  pupil  at  all,  but  complete  illumination  gives  place  to 
total  shadow.  At  this  instant,  by  means  of  a  tape-line  already  at 
hand,  the  distance  of  patient  from  observer  is  measured :  a  tape 
divided  into  centimeters  (loo  cm.  =  i  w.)  will  show  in  diopters  the 
amount  of  myopia  present. 

If  the  light  and  shadow  move  in  the  same  direction  as  the  move- 
ment of  the  mirror,  indicating  a  far  point  behind  the  observer's 
eye,  an  effort  must  be  made  to  reach  this  far  point  by  receding 
from  the  patient,  or  in  case  this  is  impracticable,  by  placing  convex 
lenses  before  the  patient's  eye  until  the  far  point  is  brought  nearer. 
The  strength  of  the  lens  to  be  chosen  can  be  approximately  esti- 
mated by  the  appearance  of  the  light  and  shaded  parts  of  the  pupil. 
If  there  is  weak  myopia,  emmetropia,  or  weak  hyperopia,  the  pupil 
shows  a  flat,  circle-like  area  of  light,  which  changes  rapidly  with 
slight  movements  of  the  mirror — a  lens  of  +j.o  D  may  be  tried. 
If,  on  the  contrary,  a  high  degree  of  hyperopia  is  present,  the  area 
of  light  is  of  smaller  diameter  and  moves  slowly  with  moderate 
rotation  of  the  mirror — for  this  try  a  lens  of  -{-5.0  to  -\-J.o  D. 
Whatever  convex  lens  has  been  used  to  bring  the  far  point  to  the 
convenient  distance  of  jo  to  50  cm.,  it  must  obviously  be  deducted 
in  the  final  estimation.  Suppose  a  lens  of  -{-5.0  D  has  displaced 
far  point  to  ^2  cm. ;  then  we  have  a  myopia  of  '^^^  =  2.§  D 
(approximately),  or  allowing  for  the  convex  lens,  we  have  (-f-j.o) 
+  (— ^o)  =  2.S  hyperopia. 

The  shadow  test  performs  the  best  service  in  measuring  astig- 
matism, since  in  applying  it  one's  attention  is  often  instinctively 
called  to  the  presence  of  that  condition.  Suppose  the  far  point  is 
in  front  of  the  observer ;  he  now  approaches  the  patient  with  slight 
movements  of  the  mirror  upward  and  downward  until  he  can  no 
longer  recognize  the  direction  of  the  movement  on  the  pupil.  He 
now  rotates  the  mirror  toward  the  right  and  left;  if  the  horizontal 
meridian  does  not  have  the  same  refractive  condition  as  the  perpen- 
dicular, there  are  still  noticeable  distinct  movements  in  the  shadow — 
movements  in  the  same  direction  with  the  mirror  if  the  far  point  of 
the  horizontal  meridian  lies  behind  the  observer,  that  is,  if  the  hori- 
zontal is  less  myopic  than  the  perpendicular  meridian.  The  move- 
ment is  against  the  mirror  if  the  far  point  of  the  horizontal  meridian 


USE   OF   THE   OPHTHALMOSCOPE.  I35 

lies  in  front  of  the  observer,  that  is,  if  the  horizontal  is  more  myopic 
than  the  perpendicular  meridian. 

If  the  principal  meridians  of  an  astigmatic  eye  are  not  perpendicu- 
lar and  horizontal  (they  usually  are  so),  we  shall  notice,  when  the 
mirror  is  rotated  around  its  perpendicular  or  horizontal  axis,  an 
obliquity  of  the  light  and  shadow  in  the  patient's  pupil,  making 
the  determination  of  the  principal  meridians  an  easy  matter,  since 
the  direction  of  these  movements  will  become  parallel  to  those  of 
the  mirror  when  the  latter  is  rotated  in  the  planes  of  the  principal 
meridians. 

Since  the  shadow  test  gives  us  the  far  point  of  the  meridian  of 
greatest  curvature  and  the  far  point  of  the  meridian  of  least  cur- 
vature, we  see  that  it  shows  not  only  the  degree  of  astigmatism, 
but  also  its  character  ;  skiascopy,  therefore,  does  better  service 
than  keratoscopy.  The  latter  is  undoubtedly  more  accurate,  but  it 
measures  only  one  condition,  the  meridian-asymmetry  of  the 
cornea,  while  skiascopy  ascertains  the  complete  error  in  the  eye, 
whether  due  to  corneal  astigmatism,  to  lens  astigmatism,  or  to  a 
disproportion  in  the  length  of  the  eyeball. 

The  errors  in  the  shadow  test  are  probably  as  great  as  in  any 
other  objective  method  for  estimating  the  refractive  conditions. 

For  an  easy  application  of  tlie  shadow  test,  various  ophtbalmologists  have  devised 
various  instruments.  In  order  to  make  a. rapid  change  of  the  lenses  in  front  of  the 
patient,  some  use  a  wheel  in  whose  edge  a  series  of  lenses  is  placed.  Others,  in  meas- 
uring the  distance  between  patient  and  physician,  attach  a  tape  measure  to  the  lenses 
placed  in  front  of  the  former.  There  is  nothing  in  all  this  essentially  necessary,  since  a 
plane  mirror,  a  case  of  test  lenses,  and  a  tape  measure  suffice  to  carrj'  out  the  shadow  test 
with  all  desirable  accuracy. 

(D)  DEMONSTRATION   OF   DIFFERENCES  OF    LEVEL   IN   THE 

FUNDUS. 

The  optic  nerve  sheath  does  not  always  lie  at  the  surface  of  the 
fundus.  A  depression  in  the  middle  has  already  been  mentioned 
as  the  physiological  excavation  (/.  124).  But  the  whole  sheath 
may  lie  at  a  greater  depth,  a  condition  that  is  always  pathological 
and  of  great  diagnostic  import.  The  presence  of  an  excavation 
can  be  demonstrated  in  two  ways  : — 

(/)  By  the  phenomenon  of  the  parallax.  For  this  purpose,  look 
at  the  inverted  image  of  the  fundus  and  move  the  convex  lens  in 
its  own  plane  upward  and  downward,  to  the  right  and  to  the  left. 
If  an  excavation  of  the  papilla  is  present,  we  see,  when  the  lens  is 


136 


OBJECTIVE    METHODS    OF    INVESTIGATION. 


moved,  an  apparent  movement  of  the  papilla's  edge  against  the 
ground  of  the  disc,  the  edge  seeming  to  be  displaced  over  the 
ground. 

This  is  illustrated  in  Fig.  j/.  Let  Pa  be  an  emmetropic  eye  with  an  excavated  disc. 
Then  from  the  point  b  (imaginary  in  this  case),  lying  in  the  retinal  surface,  a  pencil  of 
rays  (not  shown  in  the  figure)  will  emerge  from  the  cornea  parallel ;  rays  from  the  point 
a,  on  the  contrar)*,  will  emerge  convergent.  The  image  of  «,  therefore,  lies  at  n  If  the 
observer  puts  a  convex  lens,  S S,  in  front  of  the  eye,  the  image  of  a  is  produced  at  a  shorter 
distance — say  at  a' ,  and  the  image  of  b,  which  otherwise  lies  at  infinity,  is  now  at  b' . 
For  both  images,  or  rather  for  their  pencils  of  rays,  b  a'  r\%  the  ray  of  direction.  This 
is  changed  at  once  if  the  lens,  S  S,  is  displaced — say  into  the  position  marked  in  red. 
The  eye  and  the  lens  are  now  decentered.  In  each  pencil  of  rays  there  is  a  new  ray  of 
direction,  and  these  two  new  rays  of  direction  are  not  coincident.  In  the  first  pencil, 
whose  rays  emerge  from  the  cornea  parallel  to  the  axis,  d  b'  \  is  the  ray  of  direction  ; 
in  the  second  pencil,  whose  rays  emerge  from  the  cornea  convergent,  the  ray  passing 
through  the  nodal  point  of  the  red  lens  is  the  ray  of  direction.  Consequently  the  point 
b '  moves  lo  b' ' ,  the  point  a'  X.o  a' '.     An  observer  who  is  toward  the  right,  at  the  pro- 


FiG.  55  — Demonstration  of  Differences  in  Level  bv  Apparent  Displacement  of  Images. 


longation  oi  a  '  r  b  \  will  see,  when  the  lens  is  displaced  from  the  position  marked  in 
black  into  the  position  marked  in  red,  both  images  also  displaced, — a  '  ' ,  which  is  closer 
to  the  lens,  moving  the  smaller  distance,  and  b' ' ,  which  is  farther  from  the  lens,  moving 
the  greater  distance.     From  this  we  get  the  impression  that  b^  '  has  been  pushed  in  front 

This  apparent  displacement  of  points  lying  at  different  levels  depends,  therefore,  upon 
the  fact  that  the  eye  and  the  lens  become  decentered,  and  that  the  divergence  of  the  two 
rays  of  direction  increases ;  the  stronger  this  divergence,  the  greater  the  displacement. 
The  degree  of  divergence  is  only  another  expression  for  the  refractive  condition  of  the 
eye  with  reference  to  these  two  object  points,  a  and  b,  in  other  words,  an  expression  of 
their  differences  in  level. 

{2)  By  estimating  the  refractive  conditio7is  of  two  points  lying 
at  different  elevations.  This  is  done  by  the  examination  of  the 
upright  image.  Suppose  it  has  been  estimated  that  the  fundus 
{Fig.  55)  can  be  seen  by  an  emmetropic  observer  (using  no  accom- 
modation) without  a  neutralizing  lens,  and  that  the  point,  a,  is  clearly 
seen  only  by  neutralizing  myopia  in  the  patient  of — lo.o  D  ;  there 


MEASUREMENT    OF   TENSION.  1 37 

is  then  between  b  and  a  a  difference   of  refraction  of  lo.o  D,  which 
by  calculation  means  a  difference  in  depth  of  ;^.^y  mm. 

Ordinarily,  however,  the  amount  of  this  difference  is   not  calcu- 
lated, and  we  are  content  to  demonstrate  the  fact  that  it  is  present. 


IV.  MEASUREMENT  OF  TENSION. 

The  eye  may  be  termed  a  sphere  with  a  threefold  envelope — the 
sclera,  choroid,  and  retina — containing  within  it  the  lens,  the  aque- 
ous, and  the  vitreous.  The  vitreous  is  a  half-fluid  jelly  of  such  a 
nature  as  to  permit  us  to  consider  the  eye  as  a  sphere  filled  with  fluid, 
and,  therefore,  to  speak  of  the  fluid  tension  of  the  eye.  Under  normal 
circumstances  this  rises  and  falls  only  within  moderate  limits,  but  a 
decided  increase  or  decrease  in  tension  is  always  pathological,  and 
n  the  diagnosis  of  certain  diseases  is  of  great  significance. 

To  measure  this  internal  tension  in  the  eye  we  use  either  simple 
pressure  with  the  fingers  or  a  special  instrument,  the  ophthalmoto- 
nometer. Pressure  with  the  fingers  is  conducted  as  follows  :  The 
physician,  being  in  front  of  the  patient,  asks  him  to  look  downward, 
and  pushes  the  index  and  middle  fingers  between  the  roof  of  the 
orbit  and  the  eyeball  until  the  finger  points  form  something  like  a 
wedge,  which  presses  the  eyeball  downward  and  holds  it  fast.  The 
finger  points  are  thus  beyond  the  tarsus  and  are  separated  from 
the  globe  by  the  soft  parts  only.  Then  the  physician  plays  the 
finger  points  as  if  he  were  testing  for  fluctuation  in  an  abscess; 
the  impression  of  the  elasticity  thus  obtained  is  compared  with  the 
memory  of  the  resistance  in  normal  eyes,  or  in  case  only  one  of 
the  patient's  eyes  is  affected,  this  is  compared  with  the  other.  The 
immediate  comparison  of  one  eye  with  another  is  desirable,  because 
healthy  eyeballs  often  show  quite  noticeable  differences.  For  ex- 
ample, the  eyes  of  the  young  are  on  the  average  softer  than  those 
of  the  old.  The  result  of  this  test  is  expressed  as  follows  :  Normal 
Tension  =  Tn  ;  Noticeable  increased  Tension  =  Tn  -\-i ;  Decided 
Tension  =  Tn  -\-2 ;  Stone  hardness  =  Tji  -\-j.  Reduced  Ten- 
sion is  correspondingly  designated  as  Tn  — /,  Tn  — 2,  and  Tti  — j. 

It  is  evident  that  these  signs  are  just  as  inexact  as  the  method 
of  measurement  itself,  and  that  various  observers  are  by  no  means 
always  unanimous  in  deciding  whether  a  certain  eyeball  may  have 
a  normal  or  an  increase!  tension. 


138  OBJECTIVE    METHODS    OF    INVESTIGATION. 

There  has,  therefore,  been  no  lack  of  experimenting  to  devise 
some  suitable  instrument  (ophthalmotonometer)  by  means  of 
which  the  eye's  tension  may  be  estimated  independently  of  any  sub- 
jective sensation.  A  whole  row  of  tonometers  have  been  thought 
out,  but  no  one  of  them  has  become  a  fixture  in  practice,  since 
they  all  have  given  untrustworthy  results,  the  underlying  principle 
being  that  the  power  with  which  an  impress  of  a  certain  depth 
could  be  made  on  the  eyeball  would  correspond  to  the  tension 
of  the  eye.  This  is  a  false  principle.  Undoubtedly,  the  power 
necessary  to  make  an  impress  of  a  certain  depth  must  be  greater 
the  higher  the  tension  of  the  eye,  but  we  ought  by  no  means  to 
conclude  that  the  tension  of  the  eyeball  and  the  power  making  a 
certain  impress  on  it  are  proportional  to  each  other  or  in  any  way 
equal.  Tension  on  the  one  hand,  and  opposing  power  on  the  other, 
are  of  such  a  complicated  relationship  as  to  defy  mathematical 
expression,  let  alone  an  attempt  to  make  use  of  it  as  a  working 
basis. 

A.  Fick  has  recently  been  successful  in  devising  an  instrument 
free  from  theoretical  errors,  which  yields  quite  trustworthy  results. 
It  is  illustrated  in  Fig.  56.  The  tension  is  taken  from  the  capsule 
of  the  eye.  Equilibrium  can  exist  only  when  the  strain  on  any 
isolated  area  of  the  capsule  is  such  that  its  resultant  directed  in- 
ward neutralizes  the  internal  tension.  With  equal  internal  tension 
the  strain  on  the  capsule  increases  with  the  radius  of  curvature  of 
the  sphere,  because  as  the  sphere  becomes  flattened  there  is  a 
decrease  in  the  force  directed  inward.  If  the  radius  of  curvature 
in  any  part  of  the  capsule  were  infinitely  great,  that  is,  if  this  part 
were  flat,  then  no  component  of  the  strain  would  be  directed 
inward,  but  the  whole  strain  would  act  tangentially.  If,  therefore, 
I  press  flat  any  part  of  the  capsule,  the  internal  pressure  exerted 
against  this  flat  part  is  held  in  equilibrium  solely  by  the  external 
pressure,  and  that  part  of  the  capsule  and  the  strain  upon  it  do  not 
enter  into  the  calculation.  We  must  try,  therefore,  to  flatten  out 
some  part  of  the  capsule  whose  elasticity  is  known,  by  means  of 
some  force  also  known.  Then  the  internal  pressure  equals  in  hydro- 
static measure  the  external  force,  and  from  the  size  of  the  flattened 
area  the  internal  pressure  can  be  estimated. 

The  instrument  constructed  on  this  principle  is  illustrated  in  Fig. 
5(5.  It  is  quite  simple.  A  small,  flat  disk,  the  tonometer  plate,  PI, 
is  connected  with  the  spring,  7^/^,  which  is  fastened  to  the  standard, 


MEASUREMENT    OF   TENSION. 


139 


R  R.  If  this  plate  is  pressed  against  any  resisting  body,  the  spring 
is  bent,  and  its  upper  end,  provided  with  a  pointer,  moves  along 
the  scale,  T,  on  which  every  division  indicates  a  pressure  on  the 
plate  of  one  gram.  The  plate  is  just  large  enough  to  carry  /  gram 
of  mercury  2  mm.  thick.  If  we  press  on  a  scleral  area  the  size  of 
the  plate  with  a  force  of  10  grams,  that  is,  with  a  force  carrying 
the  pointer  through  10  scale  divisions,  we  know  that  in  the  interior 
of  the  eye  there  is  a  fluid  pressure  of  20  mm.  of  mercury. 


Fig.  56. — A.  Pick's  Tonometer. 


For  this  instrument  two  assumptions  are  made  : — 

(i)  That  no  unusual  power  is  needed  to  press  flat  an  area  of  the 
sclera — the  atmospheric  pressure  upon  the  inner  and  outer  surfaces 
of  the  sclera  being  the  same. 

(2)  That  the  cubic  contents  of  the  eye  is  not  appreciably  reduced 
by  the  pressure  of  this  plate  upon  the  scleral  area. 

Both  assumptions  are  admissible,  as  many  trials  by  R.  A.  Fick 
have  proved.  These  were  conducted  by  means  of  a  calf's  or  a 
pig's  eye  emptied  of  its  natural  contents  and  filled  with  water,  and 


140  OBJECTIVE    METHODS    OF    INVESTIGATION. 

then  connected  with  a  pressure  flask  and  the  manometer,  thus  ob- 
taining an  immediate  comparison  between  the  actual  pressure  and 
that  found  by  the  tonometer.  These  have  all  taught  us  that  the 
results  obtained  by  the  tonometer  are  accurate  within  very  narrow 
limits.  The  instrument  has  proved  equally  as  trustworthy  in 
man.  My  experience  has  been  that  all  the  results  are  trustworthy 
if— 

(i)  There  is  no  swelling  of  the  conjunctiva,  and  if — 

(2)  Two  observers  on  opposite  sides  of  the  plate  notice  that  it  is 
accurately  adjusted  on  the  sclera. 

This  last  point  contains  the  whole  difficulty.  If  too  strong  a 
pressure  is  applied,  a  small  wall  of  conjunctiva  is  elevated  at  the 
edge  of  the  plate  ;  if  too  weak  a  pressure  is  applied,  a  slight  crack 
is  seen  between  sclera  and  plate  ;  but  one  observer  alone  cannot 
control  with  his  eye  at  one  instant  the  entire  circumference  of  the 
plate. 

Measurements  by  A.  Pick's  tonometer  have  determined  that  a 
normal  eye  has  a  tension  of  20  mm.  of  mercury.  I  have  found  in 
glaucoma  simplex  a  tension  of  2/f.  to  j^  mm.,  in  glaucoma  absolu- 
tum  a  tension  of  50  to  60  mm. 

Maklakoff  has  also  devised  a  tonometer  on  theoretical  grounds. 
It  does  not,  as  A.  Pick's  instrument,  give  the  internal  tension  of 
the  eye  in  absolute  terms,  and  is  therefore  of  far  less  practical 
applicability  than  the  instrument  of  A.  Pick. 


PART  SECOND. 

THE  DISEASES  OF  THE  EYE. 


INTRODUCTION. 

The  variety  of  the  anatomical  structures  composing  the  eye  and 
its  surroundings  shows  very  clearly  how  one  may  divide  the  diseases 
of  the  eye  according  to  an  anatomical  scheme.  This  division  cannot, 
to  be  sure,  be  carried  out  completely,  for  on  the  one  hand  there  are 
diseases  which  depend  not  upon  changes  in  the  individual  anatomical 
structure,  but  upon  changes  of  the  eye  as  a  whole — errors  of  refrac- 
tion, for  example,  glaucoma,  panophthalmitis ;  on  the  other  hand, 
there  are  diseases  of  the  eye  for  which  we  are  not  prepared  to  give 
anatomical  explanations,  as  in  certain  forms  of  "  weaksightedness." 
Therefore,  diseases  suitable  for  anatomical  classification  must  be  put 
into  the  first  group,  and  the  others  into  the  second. 

The  order  of  arrangement  in  the  first  group  should  depend  upon 
the  system  of  examination  followed  by  the  surgeon. 

In  a  certain  sense  every  examination  ought  to  begin  with  a  short  history.  The  age, 
calling,  earlier  diseases,  and  present  symptoms  of  the  patient  should  be  noted.  In  many, 
indeed  in  most  cases,  they  are  a  valuable  signboard  for  a  closer  examination,  and  in  their 
proper  place  will  be  referred  to  again. 

The  examination  begins  with  a  view  of  the  patieiit.  After  glanc- 
ing at  his  face  roughly  to  see  whether  he  looks  ill  or  well,  whether 
there  is  any  eczema  on  the  nose  or  ears  or  angles  of  the  mouth, 
and  after  the  glands  of  the  neck  have  been  felt,  the  physician  turns 
to  the — 

(i)  Lids,  and  studies  the  condition  of  the  skin,  of  the  margins, 
and  of  the  fissure. 

(2)  Puncta  lacrimalia  and  the  neighborhood  of  the  tear  sac. 
Not  till  then  does  the  hand  touch  the  patient ;  but  now  the  lids 

are  everted  {page  18 j)  and  we  examine  the 

(3)  Co7ijiinctiva  and 

(4)  Cornea.     To  examine  the  cornea  thoroughly  simple  observa- 

141 


142 


THE    DISEASES    OF   THE    EYE INTRODUCTION. 


tion  does  not  suffice ;  we  must  make  use  of  focal  illumination  and 
the  magnifying  glass.  The  same  method  helps  us  in  examining 
also  the 

(5)  Anterior  chamber.  Iris,  and  Lens.     Finally  there  follows  the 

(6)  Ophthalmoscopic  examinatioji  of  the  interior  of  the  eye. 


?-sSSj« 


MbllsUi 


ifUlierjMusde. 


ulcautiaiuZar  orPosteriar 

J^apMari/  body  ofihe 
paipebraZ  co7yuJictu>a.. 


Oriicularcs  muscle. 


ToTSUS. 

PafyjeiraLArie/y 


Circular  ciliary  Truude 
of  Jliotcuv. 


Posterior  or  Inner S/i/e 
ofZia. 

J)aci(fa  JlcHfonuan'tJland. 


Fig.  57. — Section  through  the  Upper  Lid.    {After  Waldeyer  and  L.  Schroeter.) 


A  rigid  adherence  to  this  procedure  will  save  the  beginner  many 
a  blunder.  How  often  has  it^ happened  that  a  sore  eye  is  treated 
with  all  manner  of  washes  as  a  catarrh  until  the  patient»goes  to 
some  other  physician,  who  pulls  from  the  lid  the  irritating  lashes 
overlooked  by  the  first  one,  whose  attention  had  been  attracted  by 
the  redness  of  the  eye  itself. 


DISEASES   OF   THE    LIDS HERPES    ZOSTER    OPHTHALMICUS.       I43 


I.  DISEASES  OF  THE  LIDS. 

Anatomical  Introduction,  Fig.  §~.  The  eyelid  is  developed  in  the  embryo  from  a 
fold  in  the  skin.  During  development  the  inner  surface  of  the  lid  loses  the  histological 
construction  of  the  outer  skin  and  becomes  mucous  membrane,  the  conjunctiva  palpebra. 
A  plate  of  thickened  connective  tissue,  the  cartilage  of  the  lid,  tarsus,  gives  to  the  lid  a 
certain  degree  of  stiffness.  Between  this  cartilage  and  the  outer  skin  lies  the  closing 
muscle  of  the  eye,  musculus  orbicularis  palpebrarum.  Between  this  muscle  and  the 
external  skin  lies  a  relaxed,  elastic  connective  tissue,  poor  in  fat.  Since  the  skin  of  the 
lid  is  very  tender  and  thin,  it  is  easy  for  extravasations  of  blood,  effusions  of  blood  and 
of  water  (edema),  and  such  like  to  take  place. 

The  external  surface  of  the  lid  ends  with  the  rounded-off  anterior  lid  edge;  the  inter- 
nal surface  of  mucous  membrane  ends  with  the  abrupt  posterior  lid  edge.  Between  these 
two  lid  edges  lies  the  intermarginal  space,  which  is  .?  /t>  j  vim.  broad,  becoming  smaller 
toward  the  angles,  especially  toward  the  outer  one.  Along  the  posterior  lid  edge  one 
can  often  with  the  naked  eye  and  always  with  the  magnifying  glass  see  a  row  of  about  20 
fine  points,  the  exit  ducts  of  the  Meibomian  glands,  whose  secretion  serves  to  lubricate 
the  lid.  The  anterior  lid  edge  carries  the  lashes,  cilia,  the  upper  lid  having  100  to  ijo, 
the  lower  lid  half  as  many.  In  the  hair  bulbs  there  are  little  fat  glands,  some  large  and 
some  small,  the  Alollian  glands,  whose  exit  ducts  are  at  the  side  of  the  hair  shafts  on  the 
intermarginal  space.  The  edges  of  the  upper  and  lower  lids  unite  at  an  angle,  in  the 
canthus  externus  {Fig.  64)  and  again  at  the  canthus  internus,  which  has  the  shape  of  a 
horseshoe,  emoracing  a  small  mass  of  metamorphosed  skin,  the  caruncula  lacrimalis. 

The  lids  in  winking  act  as  a  moist  cloth  to  wash  away  all  dust,  mucus^  and  tears  from 
the  outer  to  the  inner  angle  into  the  tear  sac,  from  which  everything  fluid  is  conducted 
through  the  nasal  duct  into  the  nose,  leaving  everything  solid  at  the  inner  canthus  to  be 
removed  as  opportunity  offers  by  the  fingers  or  by  washing.  The  lids  protect  the  eye 
from  dryness  and  from  accidental  touch  by  involuntary  closure  ;  the  lashes  of  the  upper 
lid  form  a  rake  to  catch  any  dust  falling  from  the  air. 


I.  DISEASES  OF  THE  SKIN  OF  THE  LID. 

All  diseases  described  in  any  text-book  of  skin  diseases  are  occa- 
sionally found  on  the  skin  of  the  lid,  but  I  will  limit  this  descrip- 
tion to  those  few  having  especial  interest  to  the  ophthalmic  sur- 
geon. We  may  discuss  them,  therefore,  according  to  their  order 
in  the  different  layers  of  the  skin. 

{a)  Herpes  Zoster  Ophthalmicus. — This  disease  is  an  acute 
febrile  one,  and  begins  as  such  with  general  systemic  disturbance, 
prostration,  headache,  and  loss  of  appetite,  followed  by  chill  and  a 
fever.  Certain  nerves,  particularly  the  nervus  supraorbitalis,  n. 
supratrochlearis  and  infratrochlearis,  are  painful,  the  pain  growing 
so  intense  as  to  radiate  over  the  entire  side  of  the  head.  Less  often 
is  the  territory  of  the  nervus  infraorbitalis  (second  branch  of  the 
trigeminus)  involved.  These  introductory  pains  last  some  time  in 
one  case,  a  few  hours  in  another,  or  may  even  extend  over  months 


144  DISEASES    OF    THE    LIDS. 

in  a  third.  In  the  end  the  skin  disease  discovers  itself  in  the  form 
of  red  spots  that  are  confined  closely  to  the  territory  of  the  diseased 
nerve.  One  or  two  days  later  small,  watery  blisters  appear  upon 
these  red  spots  ;  this  fiuid  becomes  richer  in  cells  and  more  like  pus. 
Finally  the  blisters  dry  up,  leaving  a  crust  behind,  under  which,  in 
many  cases,  a  superficial  layer  of  the  true  skin  melts  away,  so  that 
when  these  crusts  are  thrown  off,  healing  takes  place  with  the  for- 
mation of  a  scar.  The  healing  of  the  eruption  is  by  no  means  the 
end  of  the  disease,  for  nerve  pains,  hyperesthesia,  or  anesthesia  may 
remain  for  a  long  time  afterward. 

The  essential  location  of  the  disease  is  in  the  nerve  itself  and 
that  part  of  the  Gasserian  ganglion  belonging  to  it ;  in  a  few 
autopsies  these  have  been  found  in  a  condition  of  pronounced 
inflammation.  The  cause  of  the  disease  is  not  well  known.  It  is 
recognized  by  the  eruption  along  the  course  of  the  nerve,  it  being 
a  particularly  diagnostic  point  that  the  eruption  does  not  pass  the 
middle  line  of  the  forehead  and  nose.  The  prognosis  is  good, 
assuming  that  the  nerve  twigs  supplying  the  cornea  are  not  af- 
fected. If  they  are,  the  result  may  be  ulcers  and  scars  of  the 
cornea.  Treatment  should  be  confined  to  suppressing  the  pain  by 
morphin,  and  by  powdering  the  diseased  skin  area  with  a  mixture 
of  zinc  oxid  and  starch  {Zinc.  oxid.  5.0,  Amyli  20.d)y  in  order  to 
hasten  the  drying  up  of  the  blisters.  If  crusts  have  formed,  they 
can  be  softened  by  borated  vaselin  or  any  other  mild  salve. 

{b)  Eczema. — This  is  a  protean  disease.  It  begins  as  a  shot- 
like, a  vesicular,  or  a  pustular  eruption.  This  dries  in  scales  or 
crusts.  Beneath  the  scale  lies  the  reddened  skin,  either  moist  or 
dry,  its  tissue  being  more  or  less  infiltrated,  and  sometimes  super- 
ficially eroded  or  necrosed.  The  most  prominent  subjective  symp- 
tom is  itching. 

Eczema  is  seen  on  the  lids  in  all  its  manifestations,  being  as  a 
rule  only  the  continuation  of  an  eczema  on  the  face  or  about  the 
nose  and  ears ;  or  it  may  be  the  result  of  some  disease  of  the  con- 
junctiva and  cornea  which  has  caused  an  abundant  secretion  of 
tears.  Tears  have  in  themselves  irritating  properties,  as  may  be 
seen  in  any  case  of  eyes  "  red  wept."  To  be  sure,  the  skin  is  rather 
more  resistant  than  the  mucous  membrane  of  the  eyes  and  nose, 
but  the  skin  of  the  lid  is  much  thinner  than  the  skin  of  the  rest 
of  the  body,  and  it  is  particularly  delicate  in  blond,  scrofulous 
children.     When  such  children  rub  away  with  their  little  hands 


ABSCESS.  145 

the  tears  welling  up  from  the  eyes,  the  combination  of  the  softening 
effect  of  the  moisture  with  the  mechanical  effect  of  the  rubbing 
will  easily  produce  an  eczema.  Of  special  interest  to  the  surgeon 
is  that  eczema,  relatively  seldom,  I  am  sure,  produced  by  a  wet 
bandage  saturated  with  antiseptic  fluid  (sublimate  eczema). 

The  treatment  consists  in  protecting  the  skin  and  oiling  the  lids 
with  vaselin  or  some  simple  salve.  If  there  are  scales  they  can  be 
gently  removed  after  softening  them  with  warm  oil.  Moist  spots 
can  be  protected  with  a  paste  of  salicylate  of  zinc  {Zinc.  oxyd.  lo.o, 
acid,  salicyl.  o.i,  Vaselin  lo.d),  or  with  a  salve  of  white  precipitate 
ointment  {Hydrarg.  precipitat.  alb.  i.o,  Vaseli?i  lo.d).  If  there  is  a 
superficial  erosion  beneath  the  scales,  painting  with  a  two  per  cent, 
solution  of  nitrate  of  silver  is  of  value. 

{c)  Abscess. — If  in  addition  to  the  four  known  signs  of  inflam- 
mation (calor,  tumor,  rubor,  dolor)  we  find  fluctuation  as  a  fifth, 
there  is  an  abscess.  On  the  lids  the  signs  of  an  abscess  appear  in 
certain  diseases  quite  distinct  from  each  other,  but  which  may  be 
treated  by  one  method.  The  differentiation  into  furuncle  and 
abscess  is  doubtless  pathologic,  but  is  only  of  academic  interest  to 
the  physician  as  well  as  to  the  patient. 

(a)  Furuncle. — The  disease  begins  with  a  pricking  pain,  the 
painful  spot  being  hard  to  the  touch,  owing  to  inflammatory  infiltra- 
tion. The  skin  is  red  with  a  full  capillary  injection.  All  this 
vascular  hyperemia  and  infiltration  produces  a  swelling.  The 
center  of  the  diseased  area  dies,  and  is  thrown  off  with  a  slough 
of  some  part  of  the  surrounding  surface  of  the  skin,  which  is 
replaced  by  a  connective-tissue  scar. 

Necrosis  of  a  bit  of  tissue  is  therefore  diagnostic  for  furuncle.  When  necrosis  attacks 
a  hair  sheath  with  its  adjacent  sebaceous  glands  (the  cutis  itself),  we  speak  of  follicular 
furuncle  ;  if  necrosis  begins  beneath  the  skin,  we  speak  of  cellular  furuncle ;  if  the 
necrosis  includes  a  large  section  of  the  skin,  we  call  the  disease  anthrax  or  carbuncle. 
This  is  always  severe  and  may  lead  by  sepsis  of  the  whole  body  to  death  itself.  Particu- 
larly in  the  severest  form  of  furuncular  anthrax  it  is  usually  possible  to  demonstrate 
the  cause  as  an  infection  with  an  animal  poison.  An  anthrax  carbuncle  produced  by 
inoculation  with  anthrax  bacilli  gives  a  type  of  the  condition.  Inoculation  is  generally 
brought  about  by  the  dirty  hands  of  the  patient  himself;  an  actual  wound  of  the  skin  is 
scarcely  necessary,  since  the  hair  sheaths  are,  as  C.  Hueter  states,  mouths  in  the  skin 
through  which  any  infection  may  be  carried.  Here  and  there  inoculation  may  be  brought 
about  by  the  bite  of  insects  that  have  settled  on  diseased  cattle  or  any  other  infectious 
object.  It  may  be  added,  too,  that  many  tropical  insects  carry  in  themselves  such  a  strong 
(chemical)  poison  that  their  bite  or  sting  can  produce  a  furunculous  inflammation.  In 
our  country  the  greatest  evil  of  this  kind  is  the  sting  of  bees  or  wasps,  which  can  lead, 
however,  to  no  more  than  a  severe  inflammatory  swelling. 
10 


146  DISEASES    OF   THE    LIDS. 

The  majority  of  furuncles  are  at  the  edge  of  the  lid,  and  will  be 
spoken  of  later  under  hordeolum,  though  there  are,  less  often, 
however,  genuine  furuncles  on  the  skin  itself. 

(/5)  Phlegmon,  Pseudo-erysipelas. — Lid  abscess  in  its  narrower 
sense  is  most  usually  seen  in  children,  and  generally  appears  on 
the  upper  lid.  The  lid  is  hot,  red,  and  painful.  A  spot,  at  first 
hard,  but  later  softer,  assumes  after  a  few  days  a  yellow  color,  and 
finally  points  with  escape  of  pus.  The  diagnosis  from  furuncle  lies  on 
the  one  hand  in  the  absence  of  necrosis,  and  on  the  other  in  the  more 
diffuse  character  of  the  diseased  process,  and  in  the  more  apparent 
evidence  of  fluctuation.  It  is  scarcely  possible  to  draw  a  distinction 
between  cellular  furuncle  and  abscess.  A  lid  abscess  results  gener- 
ally from  injury,  especially  a  bruise;  but  how  the  infecting  germs 
obtain  entrance  beneath  the  skin  cannot  always  be  demonstrated. 

Prognosis  of  furuncle  and  abscess  depends  upon  the  nature  and 
amount  of  infection.  As  we  cannot  estimate  this  circumstance,  we 
must  judge  by  the  appearance  and  size  of  the  area  involved. 

Treatment  consists  in  making  an  incision  as  early  as  possible 
and  with  antiseptic  precautions,  a  removal  of  diseased  tissue,  and  an 
antiseptic  bandage. 

(d)  Hemorrhage,  Hemophthalmos  externus. — A  hemorrhage 
into  the  lid  depends — 

(/)  Upon  an  injury  to  the  lid  itself  or  to  the  adjacent  tissue. 

{2)  Upon  injury  to  remote  parts,  and 

(3)  Upon  a  general  dyscrasia,  scorbutus,  for  example,  where  there 
is  no  actual  rupture  of  any  vessel,  the  blood  corpuscles  merely 
escaping  through  the  uninjured  but  abnormally  relaxed  vessel  wall. 

If  a  blood-vessel  in  a  lid  is  ruptured  a  large  quantity  of  blood 
may  be  poured  out  on  account  of  the  yielding  nature  of  the  tissue. 
The  lid  appears  bluish-red  or  black,  and  the  swelling  is  so  great 
that  the  patient  practically  loses  the  use  of  his  eye.  Laurence  says 
that  in  the  ordinary  fist  fight  of  Englishmen  the  seconds  are  accus- 
tomed to  make  occasional  incisions  into  the  puffy  lids  of  the 
fighters  and  to  squeeze  out  the  blood,  so  that  the  fight  may  proceed. 

The  Jirsi  kind  of  hemorrhage  can  be  caused 

(a)  By  a  dull  instrument. 

{d)  By  minor  surgical  operations  or  by  leech  bites  in  the  vicinity 
of  the  lids,  or 

{c)  By  rupture  of  a  blood-vessel  by  severe  coughing,  sneezing, 
or  vomitincr. 


EDEMA. 


147 


i 


The  second  kind  can  be  caused  by  fracture  of  the  skull.  For 
example,  a  fracture  of  the  roof  of  the  orbit,  or  of  the  base  of  the 
skull,  may  lead  to  a  hemorrhage  into  the  cellular  tissue  of  the 
orbit.  This  blood  becomes  visible  in  the  conjunctiva  of  the  eye- 
ball and  on  the  inner  surface  of  the  lid,  and  shows  itself  on  the 
outer  surface  only  when  it  has  passed  through  the  tarso-orbital 
fascia — the  tissue  connecting  the  lid  with  the  circumference  of  the 
orbit. 

The  third,  hemorrhage  by  diapedesis,  has  no  real  interest  for  the 
ophthalmic  surgeon.  , 

If  a  patient  is  seen  with  a  "  black  eye  "  which  he  cannot  open  on 
account  of  the  swelling,  it  is  of  first  importance  to  determine 
whether  or  not  the  eyeball  is  injured.  If  it  is  not, 
then  treatment  is  scarcely  necessary ;  the  blood 
will  disappear  of  itself  in  two  or  three  weeks  after 
having  assumed  various  shades  of  color.  If  the 
patient  insists  on  treatment,  lead  water  compresses 
and  a  pressure  bandage  may  be  prescribed. 

{e)  Edema. — The  lids  are  the  favorite  seat  for 
any  fluid  deposits,  and  they  may  become  so 
abundant  that  the  patient  finds  it  impossible  to 
open  his  eyes,  and  he  is  much  distressed  thereby. 
The  most  significant  sign  is  the  persistence  of  a 
small  dimple  when  the  swelling  is  gently  pressed 
by  the  point  of  the  finger.  These  collections  of 
lymph  in  the  skin  and  the  tissue  beneath  it  are 
only  in  part  of  an  inflammatory  nature.  When 
they  are  so  they  must  be  considered  as  indicating  a  local  disease. 
For  example,  a  lid  edema  is  a  regular  accompaniment  of  a  furuncle 
or  abscess,  and  disappears  very  quickly  when  exit  is  given  to  the 
pus.  Again,  lid  edema  is  a  very  grave  sign  when  there  is  an  in- 
flammation of  the  conjunctiva  or  bulb  or  of  the  cellular  tissue  of 
the  orbit.  Since  it  is  generally  painful  and  sometimes  mechani- 
cally impossible  to  open  the  lids  when  an  inflammatory  edema  is 
present,  the  significance  of  such  an  edema  is  often  incorrectly  in- 
terpreted. It  is  a  good  rule  to  follow,  therefore,  first  to  feel  of  the 
lid  itself — a  hard  and  particularly  sensitive  spot  indicating  furuncle 
or  abscess ;  then  to  open  the  lids,  if  necessary,  by  means  of  a 
Desmarres'  lid  elevator  {Fig.  jS). 

In  case  the  edema  can  be  traced  to  some  disease  of  the  lid,  the 


Fig.  58.— Desmarres' 
Lid   Elevator. 


148  DISEASES    OF    THE    LIDS. 

conjunctiva  will  be  only  slightly  or  not  at  all  inflamed,  the  eyeball 
normal  and  easily  moved.  If,  on  the  other  hand,  the  edema  is  of 
graver  significance,  the  conjunctiva  is  found  inflamed  and  swollen, 
the  deep  vessels  of  the  bulb  are  injected,  the  bulb  itself  prominent 
and  scarcely  movable.  (The  significance  of  this  sign  will  be  dis- 
cussed later.) 

Non-inflammatory  edema  is  also  as  a  rule  a  sign  of  disease, 
though  the  disease  may  not  always  be  so  easy  to  find.  In  some 
cases  the  edema  must  be  called  the  disease  itself  If  a  patient  is 
seen  with  edema  of  the  lids  for  which^no  local  cause  can  be  found, 
search  must  be  made  for  some  disease  of  the  heart,  kidneys,  or 
liver.  The  general  dropsy  of  kidney  disease  shows  itself  with  par- 
ticular preference  on  the  lids ;  a  light  edema,  after  scarlet  fever,  for 
instance,  being  a  hint  for  the  physician  to  think  of  scarlet  fever 
nephritis.  Again,  a  lid  edema  may  be  a  sign  of  trichinosis,  appear- 
ing toward  the  end  of  the  first  week  of  the  disease. 

It  is  scarcely  necessary  to  treat  a  lid  edema  locally  after  some 
cause  has  been  discovered,  but  in  cases  where  the  edema  must  be 
called  idiopathic  we  may  use  a  pressure  bandage  and  massage  or, 
at  the  worst,  an  excision  of  small  strips  of  skin. 

A  swelling  of  the  under  lid  and  cheek,  little  if  at  all  painful,  may  appear  after  sound- 
ing the  lacrimal  passage  and  washing  out  the  tear  sac — an  indication  that  one  must  go 
to  work  the  next  time  with  a  little  more  care.  If  pain  is  complained  of,  hot  applications 
should  be  used,  but  otherwise  treatment  is  superfluous. 

(  /")  Emphysema. — Pufifiness  of  the  lids  may  also  be  caused  by 
air,  the  presence  of  which  beneath  the  skin  may  be  recognized  by 
a  peculiar  crackling  when  pressed  by  the  finger  and  by  the  absence 
of  lasting  depression  afterward.  The  majority  of  these  cases  (by 
no  means  common)  are  produced  artificially.  It  sometimes  hap- 
pens that  a  false  passage  is  made  when  probing  the  nasal  duct ;  if 
the  patient  blows  his  nose  soon  afterward  he  may  force  air  through 
the  small  opening  into  the  subcutaneous  tissue.  But  the  physician 
is  not  guilty  of  all  cases  of  emphysema  of  the  lids.  Some  result 
from  a  fracture  which  opens  a  communication  between  the  air 
spaces  of  the  nose  or  of  a  neighboring  sinus,  and  the  orbit. 

Treatment  of  emphysema  need  be  only  palliative  ;  in  any  case 
the  patient  must  be  warned  against  blowing  his  nose  too  strongly. 

Chromidrosis. — This  disease  is  not  common  and  is  found  nearly 
always  in  women  and  girls.  It  is  characterized  by  the  appearance 
of  blue  blotches  on  the  skin  of  the  under  lid.     The  color  cannot  be 


SEBORRHEA ECZEMA.  I49 

wiped  off  while  it  is  dry,  but  with  oil  or  glycerin  it  may  be  re- 
moved ;  after  a  few  moments  it  reappears,  however.  The  cause  is 
obscure.  In  many  cases  it  has  been  demonstrated  that  the  patient 
herself  has  smeared  the  coloring  matter  on  the  skin.  In  others  a 
pathological  change  in  the  glandular  secretion  has  been  assumed. 

2.  DISEASES  OF  THE  LID  EDGE. 

{a)  Seborrhea  {Blepharitis  simplex,  Blepharadinitis). — The  patient 
complains  of  itching  and  burning — which  is  increased  by  smoke, 
dust,  heat,  continued  reading,  or  night  work — and  that  the  eyes 
tire  easily.  The  edges  of  the  lids  are  somewhat  reddened  and 
thickened.  Close  to  the  lashes  the  skin  is  covered  with  a  yellowish 
matter  or  with  crusts  and  scales.  In  the  first  case  the  seborrhea  is 
called  mo'xst,  fluida  ;  in  the  second,  dry,  sicca.  If  this  moist  or  dry 
material  is  removed  the  skin  is  found  covered  with  epidermis  of  only 
the  thinnest  structure,  the  exposed  spots  being  red  and  shiny.  The 
disease  depends  upon  an  abnormally  abundant  secretion  of  the  seba- 
ceous glands,  four  of  which  find  exit  at  each  hair-bulb.  The  lashes 
may  even  disappear,  a  condition  especially  distressing  to  women 
on  cosmetic  grounds.  The  disease  is  said  to  accompany  general 
disturbances  of  the  sexual  organs,  and  Michel  adds  syphilis  also. 

Treatment  consists  in  a  radical  removal  of  the  fat  or  scales  and 
crusts  by  washing  with  soap  and  warm  water,  a  proceeding  much 
simplified  by  softening  them  with  a  mild  salve  beforehand. 
When  the  lid  is  thus  cleansed,  an  astringent  salve  should  be  used 
{Zinc.  oxjd.  i.o,  Vaselin  lo.o) ;  Horner  recommends  sulfuretted 
mercury  {Hydrarg.  sulf.  bas.  o.i,  Vaselin  6.0). 

A  patient  will  often  complain  that  the  eyes  are  sensitive,  that  they  feel  red  and  swol- 
len, although  there  may  be  no  fatty  accumulation  or  crusts  visible.  This  condition  must 
be  designated  hyperemia  of  the  lid  edge,  a  diagnosis  to  be  used  sparingly  and  only  with 
a  mental  reservation ;  for,  as  a  rule,  there  is  behind  it  some  refractive  error,  hyperopia 
or  astigmatism,  or  some  conjunctival  inflammation  with  an  incipient  blepharitis  ciliaris. 

{b)  Eczema  {Blepharitis  ciliaris  sen  simplex.  Blepharitis  ulcerosa. 
Blepharitis  hypertrophica). — The  protean  character  of  eczema,  the 
abundance  of  hairs  and  glands  at  the  edge  of  the  lids,  the  greater 
or  less  extent  of  the  disease,  all  cause  various  pathological  pictures 
to  be  grouped  together  under  the  name  of  eczema. 

Let  us  study  first  the  picture  of  a  simple  blepharitis  ciliaris.  On 
several  parts  of  the  lid  edge  the  lashes  are  found  matted  together 
into  a  pointed  mass  embedded  in  a  yellow  crust.     If  this  crust  is 


ISO 


DISEASES    OF    THE    LIDS. 


raised  by  means  of  a  ciliary  forceps,  Fig.  jp,  preferably  from  the 
edge  upward,  a  thin  yellow  pus  will  ooze  out.  If  the  whole  mass 
with  some  of  the  hairs  be  completely  removed,  a  red,  moist  area 
will  be  seen,  indicating  that  the  epidermis  has  been  lost.  If  the 
lids  in  such  a  case  are  neglected  or  badly  treated,  or  if  the  con- 
dition is  progressive,  the  disease  extends  to  the  entire  edge,  or 
perhaps  all  four  edges  are  involved.  The  whole  lid  becomes  red 
and  swollen.  The  crusts  from  which  the  hairs  protrude  in  a  mass 
are  thick  and  often  colored  brown  with  dried  blood,  while  beneath 
them  are  seen  yellow  pus  points  partly  covered 
by  epidermis.  If  pus  and  crusts  are  removed, 
moist,  bleeding,  flat,  or  sunken  areas  are  exposed 
along  the  edge  of  the  lid — a  condition  called 
blepharitis  ulcerosa,  or  eczema  ptistulosinn,  which, 
after  continued  treatment,  may  result  in  the  con- 
dition known  as  blepharitis  hypertrophica,  corres- 
ponding to  the  final  stage  of  the  disease,  eczema 
squamosum.  The  edge  of  the  lid  is  now  found 
red  and  thickened,  covered  by  scales  and  crusts, 
while  here  and  there  can  be  discovered  a  crust, 
a  spot  either  moist  or  dry,  but  showing  a  young 
and  delicate  epidermis,  the  picture,  therefore,  of 
a  seborrhea. 

Blepharitis  ulcerosa  leaves  in  its  trail  various 
sequelae,  the  commonest  being  an  irregularity 
in  the  number  and  position  of  the  lashes.  Many 
of  the  hairs  are  entirely  destroyed  by  suppura- 
tion of  their  bulbs,  while  others  are  so  displaced 
into  a  false  direction  by  the  scar  that  they  scratch 
the  cornea,  and  these  may  escape  the  physician's 
notice,  since  they  are  smaller  and  lighter  in  color  than  normal  hairs. 
This  condition  is  called  trichiasis  {p.  /Jj).  The  intermarginal  space 
may  be  completely  lost,  so  that  the  conjunctiva  is  drawn  up  to  the 
skin  by  the  contraction  of  the  scar.  The  lids  then  always  remain 
red — ectropium  conjunctivae.  If  the  changes  due  to  the  scar  are 
very  pronounced,  the  result  may  be  an  entropium  of  the  upper  lid 
and  an  ectropium  of  the  under  one. 

Children  in  particular,  and  especially  blond  ones,  are  attacked 
by  an  eczema  of  the  lids.  Seborrhea  of  the  lid  edge  manifests  a 
tendency  to  blepharitis  in  the  same  sense  as  do  all  diseases  of  the 


F:g.  59. — Ciliary  Fok- 
CEPS,  WITH  TWO  Small 
Flat  Surfaces  for 
Seizing  THE  Hairs. 


ECZEMA.  151 

conjunctiva  and  cornea  associated  with  an  abundant  secretion  of 
mucus  and  tears.  The  last-mentioned  condition  may  be  accounted 
as  one  cause  of  blepharitis,  since  the  mucus  and  pus  of  the  con- 
junctival sac  always  contain  a  choice  collection  of  bacteria,  so  that 
the  macerating  and  inoculating  effects  of  a  conjunctival  secretion 
go  hand  in  hand.  It  is  easy  to  understand  that  dirty  children  are 
very  open  to  attacks  of  blepharitis.  Lice  of  one  kind  or  another 
may  also  cause  it.  Whether  the  ordinary  blepharitis  is  due  to  a 
bacillus  of  its  own  is  not  as  yet  capable  of  demonstration. 

Widmark,  in  each  of  twenty-five  cases,  has  detected  the  staphylococcus  pyogenes. 
This  is  obviously  no  proof  that  these  bacteria  are  the  actual  cause  of  the  disease,  and  it  is 
still  less  a  proof  that  other  bacteria  may  not  produce  the  clinical  picture  of  a  blepharitis. 

The  prognosis  of  simple  and  of  hypertrophic  blepharitis  is  favor- 
able ;  that  of  the  ulcerous  form  doubtful  or  even  unfavorable.  In 
any  case  the  disease,  even  with  proper  treatment,  will  last  for  weeks, 
the  ulcerous  form  for  months. 

Treatment  consists  in  removing  all  scales,  crusts,  and  pus,  in  en- 
couraging a  growth  of  new  epithelium  over  the  ulcers,  in  protect- 
ing the  places  already  healed  from  further  irritation,  tears,  dirt,  etc., 
and  finally  in  removing  such  results  and  conditions  as  thickening  of 
the  lids,  trichiasis,  and  so  forth.  The  first  object  can  be  most  gently 
accomplished  by  means  of  a  bit  of  cotton  saturated  in  warm  water  or 
in  a  sublimate  solution  (/  .•  ^ood) ;  whatever  is  adherent  should  be 
patiently  pulled  off  by  means  of  forceps.  With  the  same  instrument 
the  little  pus  points  should  be  opened,  and  the  cilia  glued  down  by 
the  pus  will  often  come  away  at  the  same  time.  Many  surgeons 
consider  it  necessary  to  pull  out  every  hair  having  a  diseased  root, 
but  I  have  rather  followed  Horner  in  avoiding  a  routine  epilation. 

For  the  second  object,  we  have  numerous  applications  at  our  dis- 
posal. I  apply  as  a  rule  Pagenstecher' s  "yellow  ointment,''  using 
at  the  same  time  massage  to  the  lids  if  there  are  no  ulcers.  If 
ulcers  are  present,  however,  I  paint  the  moist  areas  or  little  pits 
with  a  two  per  cent,  solution  of  nitrate  of  silver  every  alternate  day. 
A  thin  scab  then  forms  over  them  which  is  too  adherent  on  the 
following  or  intermediate  day  to  be  removed  without  injury;  on 
this  day,  therefore,  I  use  only  massage  with  the  yellow  ointment. ^ 

^  Yellow  ointment  is  prescribed  as  follows  :  — 

Hydrarg.  oxydati  flavi  via  humida  parati, I.o 

Vaselin lo.o 

In  spite  of  the  amount  of  mercury  it  contains,  the  salve  is  very  well  borne.     It  is 


152  DISEASES    OF    THE    LIDS. 

For  the  third  object,  the  treatment  of  any  disease  of  the  conjunc- 
tiva or  cornea  is  of  the  greatest  importance;  during  which  treat- 
ment any  healed  places  should  be  covered  with  a  protecting  layer 
of  fat  (yellow  ointment).  The  treatment  of  the  sequelae  will  be 
discussed  later ;  it  suffices  to  mention  here  that  massage  is  of  good 
service  in  overcoming  any  thickening  of  the  lids.  In  any  case  they 
may  be  painted  with  the  tincture  of  iodin,  although  caution  must 
be  observed  lest  a  drop  or  so  escaping  into  the  conjunctival  sac 
cause  a  painful  smarting.  The  rather  common  relapses  of  blephar- 
itis can  be  best  guarded  against  by  continued  massage  to  the  lids 
with  yellow  ointment. 

Ulcer. — The  abundance  of  glands  at  the  edge  of  the  lid,  the  thinness  of  the  epithe- 
lium, and  the  habit  man  has  of  rubbing  the  lids  with  the  fingers  whenever  the  eye  itches, 
not  to  mention  the  dreadful  custom  in  some  parts  of  the  world  (Russia  and  the  South  of 
France)  of  licking  foreign  bodies  from  the  conjunctival  sac  of  a  sufferer,  all  these  can  be 
accountable  for  the  fact  that  occasionally  ulcers  are  found  at  the  edge  of  the  lid  which 
appear  as  a  rule  only  on  other  parts  of  the  body.  Among  these  the  hard  chancre  must 
'  be  mentioned,  its  appearance  being  the  same  as  it  is  elsewhere.  The  diagnosis  demands 
the  evidence  of  an  opportunity  for  infection  as  well  as  the  cartilaginous  hardness  of  the 
edge  of  the  ulcer,  the  swelling  of  the  lymph  glands  in  front  of  the  ear,  at  the  angle  of 
the  jaw,  on  the  neck,  with  signs  of  syphilis  on  other  parts  of  the  body,  and  in  doubtful 
cases  the  success  of  a  specific  treatment. 

Vaccination  pustules  are  sometimes  found  at  the  edge  of  the  lid.  They  may  be 
developed  in  the  intermarginal  space  from  small,  superficial  pus  vesicles  having  a  diph- 
theritic appearance  and  accompanied  by  a  severe  swelling  of  the  inner  and  outer  portion 
of  the  lid  (chemosis  and  edema).  In  three  of  seven  cases  reported  by  Schirmer,  the 
cornea  was  attacked.  It  may  be  mentioned  incidentally  that  the  cow-pox  pustule  with 
its  central  indentation  is  sometimes  seen  on  the  skin  of  the  lids,  being,  of  course,  much 
less  frequent  than  those  formed  by  small-pox  in  the  intermarginal  space,  where  the  virus 
seems  to  attack  a  delicate  epithelium  even  if  the  surface  has  not  been  injured.  In  spite 
of  its  threatening  appearance,  this  generally  runs  a  favorable  course,  healing  taking  place 
without  an  appreciable  scar.  Treatment  should  be  rather  negative,  iodoform  and  a 
bandage  sufficing  in  all  cases.     Cancer  is  referred  to  on  /.  765". 

[c)  Hordeolum  {Stye,  Acne). — This  disease  attacks  young  people 
principally.  It  begins  with  a  pricking  pain  at  the  edge  of  the  lid, 
accompanied  soon  after  by  a  swelling  of  the  whole  lid,  which,  in 
case  the  upper  lid  is  the  one  attacked,  may  prevent  the  eye  from 
being  opened.  If  the  swollen  and  reddened  lid  is  stroked  with  the 
finger  a  hard  spot  will  soon  be  discovered  which  makes  the  patient 
wince  when  it  is  touched.  This  place  should  now  be  observed 
with  greater  care  by  raising  the  lid  from  the  eyeball,  when  a  yellow 

affected  by  light  so  that  it  changes  from  yellow  to  black.     It  is  best,  therefore,  to  keep  it 
in  some  non -transparent  vessel  with  a  good,  well-fitting  cover. 


TRICHIASIS.  153 

pus  point  will  be  seen  lying  either  at  the  anterior  or  posterior 
margin.  As  soon  as  this  little  point  is  opened  and  the  pus 
released,  all  the  signs  disappear  and  the  disease  is  over,  assuming 
that  the  same  process  has  not  begun  anew  at  some  other  place. 

A  pronounced  swelling  of  the  lid  may  mislead  the  physician  into 
making  a  diagnosis,  say,  of  an  incipient  blenorrhea.  The  evidence 
of  a  hard  spot  on  the  edge  of  the  lid  and  the  condition  of  the  con- 
junctiva of  the  globe  are  contra-indications,  however.  The  conjunc- 
tiva may,  of  course,  be  occasionally  swollen  with  a  simple  stye,  but 
in  this  case  it  appears  rather  pale  and  transparent  instead  of  red 
and  raw,  while  the  fluid  secreted  by  it  is  watery  and  light  colored. 

This  disease,  like  acne  of  the  skin  in  general,  depends  upon  in- 
flammation and  suppuration  of  a  hair-bulb  and  the  adjacent  sebaceous 
gland  ;  or  if  it  has  its  seat  on  the  posterior  lid  margin,  it  depends 
upon  suppuration  of  a  Meibomian  gland — a  rather  unusual  occur- 
rence. It  is  perfectly  justifiable  to  consider  the  disease  as  originat- 
ing in  an  infection  from  without,  although  this  has  not  yet  been 
proven  ;  but  the  fact  that  styes  occasionally  appear  after  massage 
of  the  eyes,  is  an  indication  that  bacteria  may,  by  mere  mechanical 
rubbing,  be  driven  into  the  open  ducts  of  a  gland.  The  tendency 
of  many  otherwise  healthy  people  to  have  styes  may  be  explained 
by  assuming  that  in  them  the  ducts  of  the  glands  are  very  patent, 
or  that  the  character  and  quantity  of  the  secretion  from  the  glands 
are  particularly  favorable  for  the  cultivation  of  bacteria. 

Treatment,  especially  when  no  pus  can  be  seen,  should  begin 
with  dry  heat\  which  not  only  lessens  the  pain  but  will  sometimes 
even  abort  the  disease.  If  pus  is  seen  it  must  be  let  out.  To  pre- 
vent a  recurrence,  cleanliness  and  disinfectants  should  be  advised. 
For  my  own  patients  I  prescribe  a  morning  and  evening  bath  to  the 
eyes  with  lukewarm  sublimate  solution  (/  .•  jooo).  In  addition  a 
sulfur  salve  (Lactis  sjilfjiris  i.o,  Vaselin  10.6)  should  be  rubbed  on 
the  edges. 

((/)  Trichiasis.' — This  name  is  applied  to  an  unnatural  position 

^  Dry  pocket  handkerchiefs  heated  in  an  oven  or  by  holding  against  a  clean  kettle 
filled  with  boiling  water  will  serve  the  purpose. 

*  In  many  text  books  trichiasis  and  distichiasis  are  treated  of  together.  But  the  normal 
lashes  of  the  upper  lid  are  not  arranged  in  rows  and  series ;  they  are  rather  planted  by 
threes  and  fours  in  the  anterior  lid  edge.  It  hap]>ens,  therefore,  that  that  bit  of  skin 
carrying  the  lashes  appears  so  divided  that  a  double  row  of  lashes  may  be  spoken  of.  This 
subdivision  has,  however,  nothing  pathological  in  it. 


154  DISEASES    OF   THE    LIDS. 

of  the  lashes,  in  which  they  are  directed  inward  toward  the  eyeball. 
The  patient  complains  that  something  is  scratching  his  eye,  that 
"  something  is  in  the  eye,"  that  he  has  caught  cold  ;  or  he  may 
make  the  correct  diagnosis  of"  wild  hairs."  Inversion  of  the  lashes 
causes  an  irritation  :  close  inspection  may  unmask  a  simple  con- 
junctivitis, or  a  corneal  ulcer,  or  even  a  pannus.  Inverted  lashes  may 
be  easily  overlooked,  since  they  are,  as  a  rule,  thinner  and  lighter 
colored  than  their  healthy  neighbors.  According  to  Michel,  the  best 
method  for  discovering  these  hairs  is  the  following :  cover  the  eye- 
ball with  a  thin  sheet  of  fluid  to  the  level  of  the  inner  edge  of  the 
lid  ;  in  the  normal  condition  a  regular  reflex  is  caught  from  the 
surface  of  the  fluid,  but  if  any  hair  out  of  line  dips  into  it,  the  regu- 
larity is  destroyed.  Corroborative  evidence  is  furnished  by  a 
magnifying  glass  with  oblique  illumination.  Even  the  thinnest 
hair  ought,  in  this  way,  to  be  detected. 

An  inversion  of  one  or  more  lashes  is  usually  the  result  of  an 
earlier  inflammation  of  the  lids,  although  trichiasis  may  be  present 
with  no  history  of  preexisting  disease,  particularly  among  people 
who,  according  to  Michel,  are  at  work  in  an  atmosphere  laden  with 
dust. 

Treatment  consists  in  pulling  out  the  inverted  hairs  with  ciliary 
forceps.  In  many  cases  this  alone  is  enough,  but  in  others  a  new 
hair  grows  in  the  same  false  direction  and  demands  a  repeated 
resort  to  epilation,  a  proceeding  unpleasant  both  for  patient  and 
for  physician.  An  effort  should  be  made,  therefore,  to  prevent  this 
new  growth  by  destroying  the  hair  bulb.  The  best  method,  but  a 
painful  one,  is  the  continuous  electric  current,  using  at  the  kathod 
a  needle  which  is  driven  into  the  bulb,  while  at  the  anod  is  a  disk 
resting  on  the  temple.  The  current  should  be  applied  about  half 
a  minute.  As  every  hair  bulb  must  necessarily  be  destroyed  by 
itself,  this  method  is  obviously  applicable  only  when  the  trichiasis 
is  reasonably  limited.  If,  as  is  not  seldom  the  case,  the  trichiasis 
is  associated  with  a  dislocation  of  the  whole  lid — entropium — resort 
must  be  had  to  the  methods  explained  on  /.  162. 

3.  DISEASES  OF  THE  TARSUS. 

Chalazion. — The  patient  visits  the  physician  rather  on   account 

of  the  displacement  caused  by  the  chalazion  than   because  of  the 

slight  irritation  proceeding  from    it.     A  chalazion   is  a  roundish 

tumor  of  the  size  and  shape  of  half  a  pea,  the  convex  side  being 


CHALAZION. 


155 


toward  the  skin,  the  flat  side  toward. the  conjunctiva.  The  skin 
covering  it  is  movable  and  normal  in  appearance;  the  conjunctiva, 
on  the  other  hand,  is  reddened  and  often,  indeed,  spongy,  looking 
as  if  a  piece  of  red  velvet  were  stuck  to  the  inner  surface  of  the 
chalazion.  If  the  tumor  is  taken  between  the  fingers  it  will  be 
noticed  that  it  is  tough,  insensitive,  and  movable  only  with  the 
cartilage;  we  have  then  obviously  a  tumor  arising  from  the  tarsus 
itself  It  is  not  uncommon  for  a  patient  to  have  several  of  these 
small  tumors,  even  on  one  lid.  The  disease  is  a 
chronic  one  and  may,  if  untreated,  continue  for 
years  in  an  unchanged  condition. 

The  anatomical  examination  of  chalazion  does 
not,  in  all  cases,  give  the  same  result,  wherefore 
many  authors,  along  with  Michel,  distinguish  be- 
tween atheroma  and  chalazion — a  differentiation 
that  is  of  little  importance  to  the  physician. 
Horner  thus  describes  the  structure  of  a  chala- 
zion :  the  outer  shell  of  the  tumor  is  composed 
of  a  dense  whitish  layer  derived  from  the  tarsus  ; 
the  inner  surface  of  this  capsule  being  supplied 
with  a  layer  of  granulation  tissue,  which  embraces 
a  space  filled  with  a  fluid  mass  of  pus  cells  and 
cholesterin.  In  other  cases  this  hollow  space  is 
lacking,  and  the  tumor  consists  entirely  of  granu- 
lation tissue. 


Opinion  is  still  divided  as  to  the  essential  character  and  cause 
of  chalazion.  Tangl  is  responsilile  for  the  most  modern  view, 
that  the  condition  is  one  of  local  tuberculosis.  The  benignity  of 
the  disease,  however,  seems  to  icontradict  this.  Deutschmann, 
after  examining  several  tumors,  is  strongly  of  the  opinion  that 
chalazion  is  not  of  tubercular  origin.  The  question  would  seem 
to  be  still  open  to  dispute. 


Fig.  60  — Entropium 
Forceps  for  the 
Upper   Right  Lid. 

The  disk  is  placed  be- 
neath the  lid,  and  the 
arm  is  screwed  down 
upon  it,  the  skin 
being  embraced  be- 
tween the  two. 


Treatment  consists  in  excising  and  curetting  the  tumor.  The 
pain  of  the  operation  can  be  overcome  by  cocain  {cocain.  muriatki 
0.2 J,  aqiice  dest.  steril.  5.0,  a  drop  in  the  conjunctival  sac  every 
minute  for  five  minutes),  especially  if  it  is  performed  on  the  con- 
junctival side.  When  the  conjunctiva  is  incised,  curetting  ought  to 
be  the  only  procedure,  and  excision  with  scarification  should  be 
avoided,  as  entropium  may  result.  The  tumor  is  reduced  in  size  by 
this  method,  but  is  not  completely  extirpated,  and  several  weeks  are 


156  DISEASES    OF   THE    LIDS. 

required  before  it  entirely  disappears.  If  the  operation  is  performed 
from  the  skin  side,  the  tumor  can  be  at  once  completely  removed. 
In  this  method  it  is  well  to  use  special  forceps  {Fig.  66)  to  avoid 
hemorrhage.  An  incision  is  made  in  the  skin  parallel  to  the  edge 
of  the  lid  down  to  the  capsule  of  the  chalazion,  from  which  a  good- 
sized  piece  is  taken ;  then  the  hole  is  curetted  with  a  sharp  spoon 
and  the  wound  in  the  skin  is  sewed  up,  although  this  last  is  scarcely 
necessary. 

Lithiasis  Palpebralis  {^Chalazion  Terretiin). — In  old  persons  there  are  sometimes 
found  little  yellow  points  about  the  size  of  a  pinhead  on  the  inner  surface  of  the  lids ;  these 
may  or  may  not  be  the  cause  of  slight  irritation  in  the  eyes.  The  contents  of  these  little 
points  consist  of  carbonate  of  lime  and  cholesterin.  They  are  situated  in  the  exit  dutts 
or  the  expanded  lobes  of  the  Meilx)mian  gland.    The  only  treatment  is  to  clean  them  out. 

Tarsitis. — .^n  acute  idiopathic  inflammation  of  this  cartilage  is  extremely  rare. 
Michel  states  that  a  subacute  or  chronic  tarsitis  is  more  frequent,  occurring  in  children 
between  seven  and  ten  years  of  age,  as  the  result  of  scruphula  or  syphilis,  and  always  on 
the  upper  lid.  This  droops  somewhat,  cannot  be  easily  elevated,  and  is  very  sensitive,  as 
may  be  noticed  when  the  attempt  is  made  to  turn  it  over.  The  cartilage  is  thickened, 
harder  than  normal,  and  its  sharp  outline  is  lost.  The  skin  is  normal  but  the  conjunctiva 
is  reddened.  Treatment  consists  locally  in  wearing  constantly  emplastrum  hydrargyri 
spread  on  linen,  with  general  medication  to  overcome  the  dyscrasia  underlying  it. 

My  experience  is  that  the  following  disease  is  not  unusual :  The  upper  lid  is  reddened, 
thickened,  and  droops.  If  it  is  everted,  there  are  seen  one  or  more  spots,  somewhat 
less  than  the  size  of  a  pea,  shining  through  the  reddened  conjunctiva.  An  incision 
releases  pus,  and  if  this  area  is  curetted,  a  prompt  cure  is  the  result. 

In  the  section,  *'  Diseases  of  the  Conjunctiva,"  the  method  of  everting  the  lids  is 
explained. 

4.  MALPOSITIONS  OF  THE  LIDS  AND  LID  EDGES. 
{a)  Narrowed  Fissure. 

The  normal  palpebral  fissure  is  in  adults  26  to  28  vim.  long  and  about  /  cm.  wide 
(high),  but  in  any  one  case  the  measurement  may  be  above  or  below  this  average,  and  the 
fissures  of  the  two  eyes  may  not  be  of  the  same  dimension.  If  the  fissure  is  narrower 
than  the  average,  the  laity  speak  of  "small  eyes  ;  "  if  wider,  of  "  beautiful  large  eyes  ;  " 
and  if,  by  any  diseased  condition,  the  fissure  becomes  narrowed,  the  laity  speak  of  "  the 
eyes  growing  small." 

An  actual  narrowing  of  the  fissure  is  distinguished  as  ankyloble- 
pharon, or  blepharo phimosis.  A  phimosis  indicates  that  a  perpen- 
dicular fold  of  the  skin  covers  the  external  angle.  If  this  is  drawn 
away  from  the  eye  toward  the  temple,  the  lid  edges  appear  normal 
and  the  fissure  is  of  the  normal  size.  This  condition  results  from 
a  contraction  of  the  skin  of  the  lid  after  a  long-continued  conjunc- 
tival catarrh.  This  is  especially  so  when  the  flabbiness  of  the  skin 
in  old  age  favors  such  a  formation  from  the  skin  of  the  temple. 


NARROWED    FISSURE.  I  57 

Ankyloblepharon  denotes  an  actual  growing  together  at  the 
external  angle  of  the  lids.  The  condition  is  occasionally  congenital, 
but  is  often  the  result  of  a  burn,  or  of  some  ulcerative  disturbance 
at  the  outer  angle. 

A  fissure  may  seem  to  be  too  narrow  when  the  upper  lid  droops, 
the  so-called  ptosis.  There  may  be  various  causes  for  this  condi- 
tion :  chalazion,  abscess,  edema,  hemorrhage,  and  inflammation  of 
all  kinds  may  weigh  down  the  upper  lid  so  that  even  a  strong  effort 
of  the  will  is  not  sufficient  to  raise  it.  The  same  is  true  in  ptosis 
adiposa,  a  condition  in  which  a  relaxed  fold  in  the  skin  becomes 
filled  with  a  yellow,  fatty  tissue,  and  therefore  causes  the  lid  to 
droop,  and  may  possibly  press  the  lashes  against  the  eyeball. 
Ptosis  may  result,  moreover,  from  an  injury  to  the  levator  palpebrae, 
and  from  a  paralysis  of  the  sympathetic  nerve,  or  of  the  oculo- 
motor. The  oculomotor  nerve  supplies  the  levator  palpebrae 
superioris  and  the  sympathetic  supplies  the  so-called  Mueller's 
muscle  {Fig.  57,  p.  142).  It  is  easy  to  distinguish  which  of  these 
two  muscles  is  the  inactive  one,  since  in  a  complete  or  partial 
paralysis  of  the  striated  levator  palpebrae  the  patient,  even  with 
the  greatest  effort,  cannot  possibly  open  the  eye  to  its  normal 
width,  but  if  the  unstriated  Mueller's  muscle  is  affected,  the  ptosis 
is  apparent  only  during  involuntary  movements,  since  by  a  decided 
effort  of  the  will  the  healthy  levator,  acting  alone,  is  able  to  open 
the  fissure  completely.  Ptosis,  again,  is  sometimes  congenital 
(acquired  perhaps  during  labor). 

One  cause  for  a  seemingly  too  narrow  fissure  is  a  cramp  or  a 
contraction  of  the  muscle  that  closes  the  eye — the  orbicularis  pal- 
pebrae. There  are  clonic  and  tonic  spasms.  A  clonic  spasm  is 
often  nothing  but  a  repeated  and  unnatural  involuntary  winking — 
nictitatio  :  but  during  the  intermissions  the  muscle  is  not  completely 
relaxed,  and  therefore  the  fissure  appears  narrow  at  all  times.  In 
other  cases  contractions  in  individual  fibers  of  the  muscle  produce 
a  like  condition,  though  obviously  this  narrowing  of  the  fissure  is 
not  a  symmetrical  one.  Such  clonic  spasms,  so-called  "fibrillary 
contractions,"  appear  in  many  persons  after  the  use  of  eserin.  In 
other  cases  they  indicate  exhaustion  from  excesses,  such  as  con- 
tinued drinking  and  other  weakening  influences.  Finally,  an  un- 
naturally frequent  winking  may  often  be  found  in  school  children. 
Here  the  indication  is  of  some  disease  of  the  conjunctiva,  doubt- 
less connected  with  error  of  refraction. 


I5o  DISEASES    OF   THE    LIDS. 

A  tonic  spasm,  especially  if  it  attacks  both  eyes,  as  it  usually 
does,  is  much  more  serious  than  a  clonic  spasm.  The  patient  is 
blind  as  long  as  the  spasm  lasts,  and  is  often  embarrassed  if  not 
endangered  thereby.  A  tonic  spasm  of  the  orbicularis — blepJiaro- 
spasimis — is  generally  of  reflex  origin  from  irritation  to  a  conjunc- 
tival or  corneal  nerve,  by  a  foreign  body  or  an  inverted  eyelash,  a 
phlyctenule  or  an  ulcer.  In  the  minority  of  cases  a  cause  for  the 
spasm  cannot  be  found  on  the  eye  itself;  the  whole  extent  of  the 
trigeminus  must  then  be  explored,  as  experience  has  taught  that  a 
hollow  tooth,  or  a  scar  pinching  a  terminal  nerve,  or  even  an  ulcer 
on  the  mucous  membrane  of  the  mouth,  is  capable  of  producing 
such  a  reflex  spasm.  If  nothing  objective  can  be  found,  "  pressure 
points  "  must  be  looked  for,  that  is,  areas  where  moderate  pressure 
by  the  finger  on  a  branch  of  the  trigeminus  produces  a  temporary 


Fig.  6i. — Ammon's  Canthoplasty. 

cessation  of  the  spasm.  In  many  cases  pressure  on  the  facial 
nerve  at  its  exit  from  the  styloid  foramen  is  said  to  stop  the  spasm, 
since  this  nerve  supplies  the  orbicularis  palpebrarum.  A  spasm 
may  also  be  of  central  origin. 

Treatment  of  ajikyloblepliaron  consists  of  an  operation  called 
canthoplasty.  The  adhesions  are  separated  by  a  horizontal  incision, 
leaving  a  wound  with  a  F-shaped  surface  {Fig.  6i).  Suitable  sut- 
ures, as  shown  in  Fig.  6i,  provide  for  proper  union  and  prevent 
readhesion  in  the  old  form. 

Blepharophimosis  can  be  corrected  by  cutting  away  a  perpen- 
dicular fold  of  skin  from  the  temple  near  the  external  canthus  ;  after 
stitching  the  edges  of  the  wound  together,  the  redundant  tissue  will 
disappear. 

Treatment  of  ptosis  will  depend  somewhat  upon  the  efforts  of  the 
patient,  since  he  can,  by  means  of  the  temporal   muscle,  draw   up 


WIDENED    FISSURE.  I  59 

the  skin  of  the  forehead  and  the  lid  connected  to  it ;  of  course,  the 
wrinkles  of  the  forehead  are  perceptibly  increased  in  size.  Another 
device  of  the  patient  is  to  throw  his  head  back.  The  physician 
directs  his  treatment  to  the  cause  of  the  ptosis.  If  there  is  any 
inflammation  of  the  lids  or  of  the  eye,  the  ptosis  itself  needs  no 
treatment,  but  if  it  is  a  sign  of  an  oculomotor  paralysis  or  of  an 
incipient  tabes  dorsalis,  treatment  must  attack  the  disease  at  the 
bottom.  The  ptosis  itself  may  be  treated  ut  aliquid  fiat  by  the  gal- 
vanic current,  by  strychnin  injections,  or  by  various  local  applica- 
tions. If  the  lid  droops  so  that  vision  is  interfered  with,  a  small 
spring  appliance  of  gold  wire  may  be  used,  which  presses  gently 
into  a  fold  of  the  skin  with  only  strength  enough  to  elevate  the 
lid,  but  not  enough  to  prevent  its  closing.  This  lid  elevator  is  the 
device  of  Dr.  Adolf  Meyer,  of  Wuerzburg,  who  successfully  over- 
came his  own  ptosis  by  its  aid. 

Operative  interference  may  be  called  for.  One  of  the  many 
operations  consists  in  cutting  away  a  horizontal  fold  of  skin.  In 
ptosis  adiposa  this  is  generally  successful,  but  the  fat  presenting  in 
the  wound  must  be  removed  at  the  same  time.  Another  operation 
consists  in  catching  up  a  horizontal  fold  of  skin  by  permanent  silver 
sutures.  A  third  proposes  to  excise  a  portion  of  the  orbicularis 
muscle  with  the  hope  of  weakening  it,  at  the  same  time  shortening 
the  lid  perpendicularly,  without  the  loss  of  any  skin.  A  fourth 
device  is  to  excise  part  of  the  tarsus  and  to  advance  the  tendon  of 
the  levator  palpebrae  superioris.  It  is  obvious  that  this  last  opera- 
tion can  be  successful  only  when  the  levator  is  not  completely 
paralyzed.  A  fifth  operation,  theoretically  the  most  practicable, 
consists  in  suturing  the  tarsus  to  the  temporal  muscle  so  that  the 
function  of  elevating  the  lid  is  thrown  upon  it. 

Treatment  of  spasm  must  likewise  attack  the  cause.  When  one 
cannot  be  discovered,  the  spasm  is  called  "  idiopathic,"  and  we 
must  comfort  the  patient  with  long-continued  galvanic  treatment, 
using  a  weak  current  with  the  positive  pole  on  any  discoverable 
pressure  point,  and  the  negative  pole  to  the  back  of  the  neck.  The 
application  should  be  made  every  day  or  every  second  day,  two  or 
three  minutes  at  a  time. 

{b)  Widened  Fissure. — The  opposite  to  ankyloblepharon  may 
be  caused  by  any  cleavage  in  the  external  canthus.  In  many  cases 
after  an  injury,  union  is  not  perfect,  especially  if  the  wound  was 
not  exactly  horizontal  but  extended  rather  downward  and  outward, 


l6o  DISEASES    OF    THE    LIDS. 

severing  the  orbicularis  fibers — a  disaster  that  may  occur  at  any 
part  of  the  muscle.  The  resulting  disfigurement  is  quite  distress- 
ing.    Epiphora  is  occasionally  an  unpleasant  accompaniment. 

A  much  commoner  cause  of  an  enlargement  of  the  fissure  is  the 
protrusion  of  the  eyeball  from  its  socket,  a  condition  called  exopJi- 
thalmos,  or  "  pop-eye  "  (see  the  chapter  on  "  Diseases  of  the  Orbit  "). 
In  a  mild  degree  this  is  noticeable  after  strabismus  operations,  such 
as  advancement  or  retirement  of  a  rectus  externus  or  internus,or  in 
myopia  due  to  a  long  axis  of  the  eyeball.  A  higher  degree  of 
exophthalmos  is  one  of  the  regular  signs  of  Basedow's  disease 
{exophthalmic  goiter).  A  most  pronounced  type  follows  corneal 
staphyloma,  or  tumors  behind  the  eyeball.  In  such  cases  the  lids 
cannot  close  completely  over  the  eyeball  even  by  a  supreme  effort, 
a  condition  called  lagophtlialmos.  As  will  be  explained  in  the  chap- 
ter on  diseases  of  the  cornea,  there  is  the  greatest  danger  to  the 


Fig.  62. — Tarsorkaphy. 


eye  from  this  condition.  Lagophthalmos  may  arise  from  still  an- 
other cause,  a  paralysis  of  the  facial  nerve  that  supplies  the  orbic- 
ularis palpebrarum  muscle — a  circumstance  that  prevents  a  closing 
of  the  lids  even  when  all  else  is  relatively  normal. 

Treatment  of  narrowed  fissure  consists  in  an  operation  called 
tarsorraphy.  The  edges  of  both  upper  and  lower  lids  are  denuded 
of  their  lashes  at  the  outer  canthus,  and  the  raw  surfaces  are  then 
sutured  together.  The  extent  to  which  this  must  be  done  depends 
upon  the  degree  of  the  contraction.  The  direction  of  the  incisions 
(a  long  one  parallel  to  the  edge  of  each  lid,  and  a  short  one  per- 
pendicular to  it,  the  two  long  incisions  meeting  at  an  acute  angle) 
is  illustrated  in  Fig.  62.  These  incisions  do  not  pass  through  the 
entire  thickness  of  the  lids  but  penetrate  the  skin  only,  and  must 
be  completed  by  the  incision  of  Flarer  (separation  of  the  lid  into 
an  anterior  and  a  posterior  plate,  see  /.  162).     In  lagophthalmos 


ENTROPIUM.  l6l 

the  tarsorraphy  does  not  entirely  correct  the  trouble ;  it  is  advisable, 
therefore,  either  to  resort  to  suturing  the  edges  of  the  lids  through 
their  whole  extent,  or  to  the  use  of  a  bandage  that  assures  thor- 
ough closure  of  the  fissure. 

(r)  Entropium  is  the  name  given  to  an  inversion  of  the  edge  of 
the  entire  lid  or  any  part  of  it.  In  the  upper  lid  the  outer  third  is 
more  often  involved,  in  the  under  lid  either  the  outer  two-thirds  or 
the  whole  lid.  There  is  usually  associated  with  it  a  trichiasis,  that 
is,  a  displacement  of  the  cilia  at  the  edge  of  the  lid.  The  unavoid- 
able result  is  an  irritation  to  the  eye,  giving  rise  to  pain,  lacrima- 
tion,  and  spasm.  If  the  cornea  is  annoyed  by  these  irritating  hairs 
for  a  long  time,  there  will  result  small  or  large  ulcers  or  the  so- 
called  keratitis  pannosa,  characterized  by  haziness  and  the  forma- 
tion of  new  blood-vessels. 

There  are  several  causes  for  entropium.  A  spasm  of  the  orbicu- 
laris is  one,  and  some  persons  can  produceavoluntary  entropium  by 
this  means.  In  others  this  spasmodic  contraction  and  the  resulting 
entropium  takes  place  involuntarily,  if  the  conjunctiva  or  cornea  be 
painfully  irritated.  Every  spasmodic  closure  of  the  eyes  does  not, 
however,  produce  entropium,  so  we  must  suppose  that  some  par- 
ticular circumstance  favors  it ;  and  we  do,  in  fact,  find  such  a  con- 
dition in  a  narrowed  fissure,  a  relaxed  skin,  or  flabby  tarsus,  or  an 
absorption  of  the  natural  fatty  cushion  in  the  orbit.  The  aged  are 
regularly  victims  to  some  of  these  conditions,  and,  therefore,  we 
often  see  entropium  in  old  persons  whose  eyes  have  been  bandaged, 
since  a  bandage  obviously  encourages  inversion  of  the  lids  by  pres- 
sure upon  them.  Entropium  from  this  cause  is  called  spastic,  and 
attacks  with  preference  the  lower  lid.  A  second  and  very  common 
cause  of  entropium  is  a  cicatricial  contraction  of  the  conjunctiva 
with  a  distortion  of  the  tarsus,  usually  the  result  of  trachoma,  the 
conjunctiva  and  tarsus  of  the  upper  lid  suffering  most,  a  condition 
called  cicatricial  entropium. 

The  diagnosis  is  easy,  but  a  simple  trichiasis  should  not  be  mis- 
taken for  it.  In  trichiasis  the  edge  of  the  lid  is  normal,  but  the 
cilia  are  displaced.  In  pure  entropium  the  reverse  is  the  case.  Of 
course,  the  cilia  may  be  displaced  on  an  entropianized  lid,  just  as 
we  may  find  inverted  lashes  on  an  ectropianized  lid. 

Treatment  of  spasmodic  entropium  often  requires  only  some 
slight  modification  in  the  bandage;  or  one  end  of  a  strip  of  plaster 
may  be  fastened  close  below  the  lashes,  and,  after  they  have  been 


l62  DISEASES    OF    THE    LIDS. 

drawn  into  place,  the  other  end  should  be  attached  to  the  cheek. 
If  these  simple  means  do  not  suffice,  an  operation  must  be  per- 
formed. Gaillard's  suture  seems  to  be  most  in  use  and  is  made  in 
the  following  way  :  Raise  the  skin  with  a  bit  of  the  muscle  beneath 
into  a  horizontal  fold  parallel  to  the  under  lid,  and  pierce  the  base 
of  this  fold  perpendicularly  from  below  upward,  so  that  the  point 
of  the  needle  makes  its  exit  j  to  .^  7nin.  below  the  edge  of  the 
lid ;  now  reverse  the  needle;  and  about  2  mm.  from  the  point  of 
exit  enter  the  needle  again  and  carry  it  downward  through  a  fold 
of  the  skin,  tying  a  knot  over  a  roll  of  cotton.  Two  or  three  of 
such  sutures  may  be  made  along  the  lid.  After  two  days  the 
threads  are  to  be  taken  out.  The  scars  corresponding  to  the  paths 
of  the  thread  are  said  to  make  the  immediate  effect  of  the  suture  a 
permanent  one. 

I  have  seen  so  many  failures  after  Gaillard's  suture  for  entropium  that  I  have  aban- 
doned the  method.  Instead  of  it  I  prefer  the  classical  excision  of  a  horizontal  fold  of 
skin  parallel  to  the  edge  of  the  lid,  with  a  suture  of  the  wound.  I  have  never  known 
failure  from  this. 

If,  however,  the  desire  is  only  temporarily  to  prevent  a  bandage  from  causing  entro- 
pium, I  have  always  been  satisfied  with  the  following  suture :  I  enter  the  needle  about 
I  cm.  inward  from  the  external  canthus,  and  push  it,  as  may  seem  best,  2,  3,  or  even 
^  cm.  beneath  the  skin  outward,  or  outward  and  downward.  After  bringing  it  out  I  tie 
the  ends  of  the  threads.  The  skin  thus  caught  up  is  formed  into  a  sort  of  tumor,  the  lid 
being  actively  stretched  and  drawn  away  from  the  eye.  Of  course,  the  thread  gradually 
cuts  into  the  skin  and  its  efficacy  is  consequently  lost,  but  as  soon  as  the  bandage  is  un- 
necessary, the  thread  should  be  removed. 

A  successful  treatment  of  cicatricial  entropium  demands  a  more 
radical  interference.  As  the  edge  of  the  lid,  in  this  case,  will  not 
yield  to  moderate  traction,  it  must  first  be  made  movable.  This 
can  be  done  by  Flarer's  incision,  which  is  made  a  few  millimeters 
deep  at  the  intermarginal  part,  and  splits  the  lid  into  an  anterior 
and  a  posterior  layer, — the  anterior  carrying  all  the  lashes  with  their 
hair  bulbs  and  glands,  and  the  posterior  consisting  of  tarsus  and 
conjunctiva,  while  the  length  of  the  incision  is  proportionate  to  the 
length  of  the  entropianized  part  of  the  lid.  The  excision  of  a  fold 
in  the  skin  parallel  to  the  edge  of  the  lid  is  made  after  this.  The 
edge  of  the  lid  is  thus  made  movable.  If  the  wound  parallel  to  the 
edge  of  the  lid  is  now  closed  by  perpendicular  sutures,  this  mov- 
able edge  will  yield  to  traction  on  it,  and  there  will  remain  a  nar- 
row wound  beneath  the  edge  of  the  lid  (if  the  upper  lid  has  been 
operated  on).     This  linear  wound  surface  was  formerly  left  to  itself. 


ECTROPIUM.  163 

but  recently  it  has  been  covered  by  means  of  epidermis  transplan- 
tation ;  that  is,  small  bits  of  skin  taken  from  the  upper  arm  and  so 
excised  that  only  the  tops  of  the  papillae  are  cut  off.  Others 
use  as  a  covering  that  portion  of  the  skin  of  the  lid  which  has  just 
been  removed,  but  in  this  case  it  is  not  completely  severed,  being 
released  only  enough  to  be  able  to  shove  it  beneath  the  bridge 
made  by  the  lower  incision.  The  operation,  after  it  is  ended,  seems 
to  leave  a  clumsy  result,  but  at  the  end  it  is  generally  quite  success- 
ful. Thier  prefers  to  sever  the  flap  before  using  it  as  a  cover:  the 
wound  is  first  carefully  sutured  and  then  the  flap  is  transplanted  to 
the  intermarginal  part  and  pressed  into  this  wound  by  sutures  pass- 
ing around  it  from  the  anterior  to  the  posterior  edge.  By  these 
methods  the  tissue  carrying  the  lashes  is  placed  in  a  new  position — 
a  process  called  "  Transplantation  of  the  ciliary  floor." 

{d)  Ectropium. — The  slightest  degree  of  ectropium  is  termed 
eversion,  by  which  is  meant  a  moderate  elevation  of  the  edge  of 
the  lid  from  the  eyeball.  In  the  highest  degree  of  ectropium,  not 
only  is  the  edge  of  the  lid  but  also  the  entire  lid  turned  outward. 
Ectropium  most  commonly  attacks  the  under  lids,  either  limited  to 
the  inner  or  outer  canthus,  or  extended  through  the  entire  length 
of  the  lid. 

The  results  of  moderate  ectropium  are  by  no  means  so  severe  as 
those  of  entropium.  The  most  important  is  epiphora,  which  shows 
itself  if  the  inner  angle  of  the  lid  is  only  slightly  everted,  but 
enough  to  bring  the  inferior  punctum  lacrimalium  out  of  the  tear- 
sea.  Epiphora  by  itself  is  only  harmful  through  the  eczema  it  in- 
duces in  the  skin.  If  the  eversion  is  so  complete  that  the  con- 
junctiva is  unprotected,  hypertrophy  results  and  the  conjunctiva 
looks  like  raw  flesh — a  condition  called  ectropium  sarcoinatosiim. 
On  account  of  this,  as  well  as  of  the  infiltration  of  tissue  arising 
from  the  eczema,  the  lid  becomes  heavier  and  less  able  to  assume 
the  normal  position.  In  this  condition,  old  persons  may  run  about 
from  year  to  year  without  the  courage  to  undergo  an  operation  or 
even  to  ask  the  advice  of  a  physician.  Such  a  "  blear-eyed  "  person 
looks  bad,  but  he  does  not  look  badly ! 

Just  as  spasm  of  the  orbicularis  leads  to  entropium,  so  is  a  paral- 
ysis of  that  muscle  a  frequent  cause  of  ectropium.  This  paral- 
ysis need  not  be  complete;  a  mere  muscular  weakness  suffices,  a 
condition  seen  in  advanced  life,  particularly  if  the  skin  hangs  down 
in  flabby  folds,  and  when  the  patient  adds  to  a  beginning  eversion 


164  DISEASES    OF   THE    LIDS. 

by  continually  trying  to  wipe  off  the  lid.  Such  an  ectropium  is 
called  paralytic  or  senile,  and  usually  begins  at  the  nasal  angle. 

Another  cause,  the  tension  of  a  scar,  leads  to  cicatricial  entropium. 
As  a  rule,  this  results  from  some  earlier  disease  which  has  destroyed 
the  symmetry  of  a  part  of  the  lid.  Caries  of  the  orbit  in  children 
is  the  commonest  cause  of  adhesion  between  skin  and  bone.  The 
upper  as  well  as  the  lower  lid  may  suffer  from  this  ectropium,  the 
favorite  seat  of  such  a  scar  being  the  edge  of  the  orbit,  either 
above  or  below  and  at  the  outer  angle.  Burns,  lupus,  syphilis, 
small-pox,  etc.,  are  less  common  causes. 

The  prognosis  is  always  grave,  especially  if  the  eversion  is  so 
considerable  that  the  eyeball  is  never  quite  covered  (lagophthalmos). 
Such  a  condition  threatens  the  cornea  and  vision  as  well. 

Treatment. — In  the  simplest  cases  (eversio  simplex)  this  consists 
in  slitting  up  the  lacrimal  canal,  sounding  the  nasal  duct  (/.  iy6  et 
seq),  and  cautioning  the  patient  not  to  wipe  the  eye,  as  he  usually 
does,  from  above  and  inward  toward  the  temples,  but  to  rub  it  in  the 
opposite  direction.  Epiphora,  with  its  attendant  evils,  is  corrected, 
and  the  malposition  itself  is  overcome  by  this  orthopedic  massage. 

If  this  simple  means  is  not  sufficient,  resort  must  be  had  to 
Snellen's  suture,  which  is  preferred  by  the  patient  who  objects  to 
an  operation  but  has  no  fear  of  a  simple  thread.  For  this  purpose 
take  several  silk  threads,  each  thread  being  armed  at  each  end 
with  a  needle  ;  enter  the  two  needles  of  the  thread  on  the  con- 
junctival side  of  the  lid  from  above  downward  ;  bring  them  out 
onto  the  skin  at  about  the  level  of  the  edge  of  the  orbit  and  knot 
the  ends  over  a  roll  of  cotton.  It  should  not  be  forgotten  that 
the  lashes  may  be  in  a  position  of  trichiasis  in  spite  of  the  existing 
ectropium,  and  that,  if  the  lid  is  replaced  to  the  normal,  they  may 
be  brought  against  the  eyeball.  The  direction  of  the  hairs,  there- 
fore, must  always  be  of  the  first  importance. 

In  severe  cases  of  paralytic  ectropium  there  are  numerous 
operations  all  designed  to  raise  the  under  lid  or  to  stretch  it  out 
horizontally.  The  first  aim  is  met  by  tarsorrapliy  [p.  166).  If  this 
is  not  successful  it  may  be  combined  with  the  excision  of  a  tri- 
angular piece  of  skin  close  to  the  outer  canthus  {Fig.  6j).  If  a  is 
united  to  a'  and  d  to  d',  the  result  is  plainly  to  raise  the  lower  lid 
and  to  put  it  on  the  stretch. 

I  have  always  had  a  satisfactory  outcome  from  an  operation  originally  planned  for  the 
extirpation  of  a  tumor  of  the  lid  (see/.  i66). 


COLOBOMA — EPICANTHUS CANCER. 


165 


In  cicatricial  ectropium  the  first  step  is  to  sever  the  adhesion 
between  lid  and  bone,  and  then  to  bring  about  reposition  by  any  of 
the  methods  mentioned  above,  and  to  cover  any  remaining  scar  by 
a  flap  from  some  adjacent  part. 

Coloboma. — This  name  is  given  to  an  unusual  and  congenital  defect,  the  evidence  of 
which  lies  in  a  perpendicular  fissure  in  the  edge  of  the  lid.  It  involves  the  whole  thick- 
ness of  the  lid  in  the  shape  of  a  wedge  with  its  base  at  the  edge  of  the  lid.  At  the  apex 
of  the  wedge  a  small  bridge  of  skin  sometimes  connects  the  two  sides,  while  beneath  this 
bridge  the  fissure  penetrates  muscle,  tarsus,  and  conjunctiva.  The  defect  is  usually  found 
in  the  upper  lid,  either  at  the  middle  or  toward  the  inner  canthus.  There  are  generally 
other  anomalies  connected  with  it,  such  as  harelip  and  fissure  of  the  palate. 

A  similar  fissure  may  be  caused  by  wounds  (/.  i^g),  and  this  is  also  called  coloboma. 
To  prevent  this,  the  edges  of  any  wound  should  be  carefully  approximated.  In  case 
there  is  still  a  fissure  after  union,  freshen  the  edges  and  suture  again. 

Epicanthus. — In  persons  with  flat  noses  and  relaxed  tissue,  such  as  babies,  Mon- 


FiG.  63.— Operation  for  Ectropium.     (After  Dieffenbach.) 

golians,  or  syphilitics  with  saddle  noses,  a  perpendicular  fold  of  skin  from  the  nose  may 
cover  the  inner  canthus;  the  free  edge  of  the  fold  being  slightly  curved,  the  concave  side 
toward  the  temple.  \.s  the  condition  appears  nearly  without  exception  on  both  sides, 
the  nose  looks  very  broad  and  ugly.  This  is  called  epicanthus.  When  congenital, 
treatment  is  seldom  necessary,  for  the  growth  disappears  of  itself  as  the  nose  grows  larger 
with  increasing  years.  In  syphilitics  an  excision  of  a  perpendicular  fold  of  skin  at  the 
bridge  of  the  nose  will  obliterate  the  deformity.      The  operation  is  called  rhinorraphy. 


5.  NEW  GROWTHS. 

The  literature  will  show  that  every  variety  of  tumor  is  to  be 
found  on  the  lid,  but  only  the  most  important  will  receive  mention 
here. 

Cancer. — This  is  undoubtedly  the  most  important  new  growth 
on  the  lid  which  the  surgeon  has  to  treat.  It  appears  only  in  adult 
life,  from  forty  years  and  upward.     As  a  rule  it  arises  from  the  edge 


l66  DISEASES    OF    THE    LIDS. 

and  probably  from  a  sebaceous  gland.     It  occurs  most  commonly 
upon  the  inner  half  of  the  lower  lid. 

Michel  distinguishes  a  flat,  a  deep,  and  a  papillomatous  form  of 
cancer.  A  characteristic  of  all  forms  is  a  small,  hard,  knotty  tumor 
at  the  edge  of  the  lid,  which  ulcerates  in  the  center  while  it  spreads 
at  its  margin  by  the  addition  of  new  nodules.  The  flat  kind  is 
distinguished  by  a  shallow,  indolent  ulcer,  cicatrizing  easily  ;  the 
deep  kind  has  a  crater-like  ulcer  of  rapid  growth,  dark  red  in  color, 
with  hard  edges,  inducing  an  inflammatory  reaction  of  the  whole 
lid;  \h^ papillomatous  kind  has  spongy  hypertrophied  tissue  that 
bleeds  easily,  giving  to  the  surface  a  lumpy  or  flap-like  appearance. 
The  surgeon,  however,  is  interested  more  in  the  diagnosis  of  cancer 
itself  than  in  any  fine  differentiation  concerning  it.  A  hard  chancre 
affords  the  most  chance  for  a  mistake,  but  a  syphilitic  sore  arises 
from  contact,  probably  acknowledged  by  the  patient.  It  grows 
rapidly ;  the  lymph  glands  near  the  ear,  at  the  angle  of  the  jaw,  and 
on  the  neck  are  early  involved  ;  and  finally  edema  is  more  apparent. 
In  cancer  we  have  more  advanced  age,  slower  development,  and  a 
later  involvement  of  the  lymph  glands. 

Tuberculosis  must  also  be  thought  of.  I  have  just  operated  on  a  tumor  supposed  to 
be  cancerous,  but  a  histological  examination  made  by  Dr.  Hanau  showed  tubercle  in  the 
form  of  lupus. 

Treatment  of  cancer  consists  in  excision.  So  long  as  the  tumor 
is  small,  the  following  method  will  afford  a  permanent  cure  :  Let  an 
assistant  seize  the  edge  of  the  lid  with  a  forceps  on  each  side  of  the 
tumor,  to  stretch  the  part  to  be  operated  upon  and  to  prevent  bleed- 
ing ;  then  the  surgeon  cuts  between  the  forceps  in  healthy  tissue 
with  scissors,  embracing  the  whole  thickness  of  the  lid  and  making 
a  wedge  with  its  base  to  the  edge  of  the  lid.  The  V-shaped  wound 
thus  formed  is  united  by  conjunctival  sutures  first,  and  by  skin 
sutures  afterward.  If  the  cancer  has  attacked  the  conjunctiva,  the 
operation  must  be  more  extensive,  even  to  removal  of  the  eyeball 
in  certain  cases. 

Verrucae  {Warts). — These  are  usually  discovered  by  accident,  when  the  patient  is 
seeking  advice  for  some  other  ailment,  never  having  noticed  these  small  tumors.  As  a 
rule  the  wart  lies  at  the  outer  angle  and  has  a  broad  base.  The  surgeon  must  remember 
that  such  a  tumor  in  an  old  person  may  eventually  develop  into  cancer,  or  it  may  end  in 
a  horn,  cornu  cutaneum,  as  is  occasionally  seen  in  both  old  and  young.  They  should  be 
removed  by  scissors  curved  on  the  flat,  or  by  cautery  if  the  patient  fears  the  knife,  though 
the  cautery  is  actually  more  painful  in  the  end. 

Transparent  cysts  of  the  edge  of  the  lid  are  quite  benign  ;  they  result  from  occlu- 


ANGIOMATA — XANTHELASMA.  I67 

sion  of  an  exit  duct  of  a  sweat  gland.  Its  contents  is  a  clear  fluid,  and  may  be  let  out  by 
an  incision. 

Argiomata  (  Vascular  Tumors). — These  are  of  two  kinds — telangiectatic  and  caver- 
nous. The  first  variety  characterizes  the  congenital  red  blotches  vulgarly  called  birth  marks, 
which  are  composed  of  dilated  blood-vessels  shining  through  the  epidermis.  They  may 
disappear  spontaneously  in  later  life,  although  they  sometimes  increase  in  size,  after  lying 
quiescent  for  years.  The  cavernous  angioma  is  distinguished  from  the  other  by  the  fact 
that  it  protrudes  above  the  surface  and  is  thus  a  real  tumor ;  it  distorts  the  upper  lid  or 
impairs  its  usefulness  by  preventing  its  proper  elevation  (ptosis).  The  cavernous  angioma 
has  still  other  characteristics  ;  it  is  bluish-red  in  color,  and  pressure  upon  it  will  for  the 
moment  obliterate  the  whole  tumor.  If  the  patient  desires  the  removal  of  an  angioma, 
it  may  be  accomplished  by  excision  or  by  the  cautery ;  but  if  the  growth  seems  too  large 
for  a  safe  operation  it  should  be  made  to  atrophy  by  introducing  platinum  wires  and  then 
raising  them  slowly  to  a  red  heat  by  means  of  the  electric  current. 

Xanthelasma  [Xanthoma). — There  are  two  kinds — xanthoma  planum  and  xan- 
thoma tuberosum.  The  first  appears  nearly  always  as  an  egg-shaped  or  irregular  blotch 
on  the  fold  of  the  upper  lid,  above  the  inner  tarsal  ligaments ;  it  is  dirty  yellow  in  color, 
and  varies  in  diameter  from  /  to  ^  mm.  After  a  time  new  blotches  appear  near  the 
original  one,  and  the  disease  may  pass  to  the  lower  lid  or  may  attack  the  other  eye,  so 
that  in  the  course  of  years  both  eyes  may  be  surrounded  by  a  group  of  yellowish  spots. 
The  disease  is  said  to  be  an  hypertrophy  of  connective-tissue  cells  in  the  cutis,  with  sub- 
sequent fatty  degeneration  of  these  cells.  Xanthoma  tuberosum  is  made  up  of  small, 
light-yellow  nodules,  lying  generally  on  the  skin  of  the  nose.  They  result  from  occlu- 
sion and  hyperplasia  of  sebaceous  glands.  If  removal  is  desired  they  may  be  excised. 
Stem  has  recently  stated  that  cauterization  with  10  per  cent,  sublimate  collodion  will 
completely  bleach  these  yellow  spots  without  destruction  of  tissue. 


II.  DISEASES  OF  THE  LACRIMAL  APPARATUS. 

Anatomical  and  Physiological  Introduction. — Tears  contain,  according  to  Arlt,  o.j2  per 
cent,  albumin  and  i.2§j  per  cent,  sodium  chlorid.  This  large  amount  of  sodium  chlorid 
in  proportion  to  that  in  other  fluids  of  the  human  body  gives  to  tears  their  salty  taste,  and 
is  accountable  for  the  irritation  they  cause  to  the  mucous  membrane  of  the  eye  and  of 
the  nose.  The  amount  of  tears  secreted  is,  under  ordinary  circumstances,  very  small ;  but 
it  can  be  remarkably  increased  at  any  moment  by  irritation  to  the  conjunctiva,  cornea, 
optic  nerve,  to  the  nose,  and  finally  by  mental  excitement.  Tears  are  secreted  by  the 
glandulie  lacrimalis.  Each  eye  has  two  glands,  an  upper  and  a  lower.  The  upper  lies 
in  a  pit  in  the  roof  of  the  orbit,  the  fossa  glandulse  lacrimalis  ;  the  lower  and  smaller  one 
is  separated  from  the  upper  by  a  slight  fascia  ;  it  lies  directly  against  the  conjunctiva,  and 
in  many  individuals  can  be  seen  through  it  if  the  upper  lid  is  everted  with  the  eye  directed 
strongly  downward.  The  ducts  of  both  glands  have  exit  in  the  outer  and  upper  fold  of 
the  conjunctival  sac,  from  which  the  tears  flow  between  the  lids  and  the  eye  toward  the 
nose  into  the  lacrimal  sac,  a  space  bounded  outwardly  by  the  plica  semilunaris,  inwardly 
by  the  edge  of  the  inner  canthus,  above  and  below  by  the  caruncles.  (Goldzicher  and 
Jendrassik  have  recently  declared  that  the  secretory  nerve  of  the  lacrimal  gland  is  not  the 
lacrimal  branch  of  the  first  division  of  the  trigeminus,  but  belongs  to  the  facial  nerve. 
In  a  complete  facial  paralysis,  therefore,  of  central  origin,  the  secretion  of  tears  on  the 
affected  side  would  cease,  and  in  mental  excitement  there  would  be  "  one-sided  weeping.") 


1 68 


DISEASES    OF    THE    LACRIMAL   APPARATUS. 


To  get  an  idea  of  the  course  of  the  tears,  place  a  cover  glass  on  a  slide  and  put  a 
drop  of  water  on  one  side  of  the  glass;  the  water  will  then,  by  "capillary  attraction,'' 
be  drawn  between  the  two  glasses.  If  now  a  bit  of  blotting  paper  be  held  on  the  oppo- 
site side  of  the  cover  glass  the  water  will  be  sucked  up  by  it.  The  two  glasses  represent 
lids  and  eye,  the  blotting  paper  the  lacrimal  apparatus. 

This  lacrimal  apparatus  {Fig.  64)  begins  with  the  two  puncta  lacrimalia,  superius  et 
inferius  ;  the  passage  enters  perpendicular  to  the  lids  for  a  millimeter,  then  turns  nearly 
at  right  angles  and  proceeds  in  the  direction  of  the  lid  as  the  canaliculus  toward  the  nose. 
The  canaliculi,  either  together  or  separately,  open  into  the  outer  wall  of  the  tear  sac,  saccus 
lacrimalis,  a  space  lined  with  mucous  membrane,  lying  behind  the  inner  palpebral  tendon 
in  the  fossa  lacrimalis,  and  having  an  upper  blind  end,  the  fundus,  somewhat  above  the 
tendon.  This  inner  palpebral  tendon  is  seen  as  a  yellowish  cord  in  the  skin,  when  the 
external  angle  is  dragged  toward  the  temple.  The  passage  now  proceeds  perpendicu- 
larly downward  from  the  sac,  as  the  ductus  naso-lacrimalis,  finally  opening  into  the  inferior 
meatus  of  the  nose.     This  naso-lacrimal  duct  is  contracted  in  two  places,  the  beginning 


t  Sa-ccus  Zack/y^i 
Canaliculus  ladm 


J)uciiLS7iaso2cu^y< 


Fig.  64. — Scheme  of  the  Lacrimal  Passage. 
The  lower  punctum  and  the  upper  canaliculus  are  not  indicated  by  name. 


and  the  end.     It  is  lined  with  mucous  membrane  similar  to  that  of  the  nose,  and,  partic- 
ularly at  its  lower  half,  is  embedded  in  a  venous  flexus. 

The  naso-lacrimal  duct  is  not  exactly  perpendicular  nor  exactly  straight.  Its  deviation 
from  the  straight  line — called  the  S  curve — is  of  no  practical  importance.  The  deviation 
from  the  perpendicular  must  be  borne  in  mind,  for,  according  to  the  shape  of  the  skull, 
the  passage  curves  more  or  less  backward  ;  while  if  the  nose  is  narrow  it  curves  some- 
what inward.  Strictures  occur  most  frequently  at  the  upper  and  lower  orifices.  The 
tears  collected  at  the  inner  canthus  flow  through  this  passage  into  the  nose.  The  forces 
at  work  are  capillary  attraction,  gravity,  and  the  movements  of  the  lids.  That  these 
movements  directly  assist  in  emptying  tears  into  the  nose  can  be  easily  understood  when 
we  remember  that  by  winking  rapidly  we  prevent  an  overflow  of  tears  when  they  are 
secreted  too  freely,  and  the  nose  "  runs  "  when  we  cry.  Henke  has  analyzed  the  effect 
of  a  wink.  He  compares  this  to  a  suction -pressure  pump,  but  other  investigators  do  not 
uphold  him  in  every  respect.  The  accepted  idea  is,  that  in  winking  the  tear  sac  is  ex- 
panded by  the  traction  of  the  muscles  and  the  tears  sucked  into  it,  but  that  the  contrac- 
tion of  the  sac  is  only  passive,  due  to  the  elastic  action  of  tense  tissues. 


ABSCESS — INFLAMMATION — NEW    GROWTHS.  169 

I.  DISEASES  OF  THE  LACRIMAL  GLANDS. 

(a)  Abscess  of  the  lacrimal  gland  is  an  extremely  rare  disease, 
and  the  diagnosis  of  such  may  always  be  questioned.  The  diagno- 
sis depends  upon  the  signs  of  abscess  at  the  upper  and  outer  angle 
of  the  orbit,  but  this  does  not  exclude  the  probability  that  the 
gland  itself  may  be  healthy  and  the  abscess  a  process  going  on  in 
the  adjacent  orbital  tissue  (see  Diseases  of  the  Orbit).  The  fact 
that  the  incision  into  such  an  abscess  often  reaches  denuded  bone 
rather  corroborates  this  latter  supposition. 

{U)  Inflammation  of  the  lacrimal  gland  is  also  very  rare,  but  has 
been  actually  observed. 

The  diagnosis  depends,  not  so  much  upon  the  presence  of  swell- 
ing in  the  neighborhood  of  the  gland,  as  upon  the  fact  that  the 
swollen  gland  can  be  seen  and  felt.  The  lid,  especially  when  the 
inflammation  is  severe,  must  of  course  be  red  and  swollen,  and 
difficult  to  elevate.  In  cases  reported  by  v.  Graefe,  Heymann,  and 
V.  Wecker,  the  eye  itself  was  inflamed  on  account  of  excessive 
secretion  of  tears.  In  a  case  reported  by  Horner,  no  cause  could 
be  discovered  unless  we  call  "  catching  cold  "  a  cause.  This  case 
is  likewise  remarkable  in  that  the  disease  appeared  on  both  sides 
and  that  the  lobular  structure — generally  not  appreciable — was 
plainly  evident  to  the  fingers. 

Treatment  consists  of  inunctions  of  mercury  and  iodid  of  potas- 
sium salve ;  healing  may  result  in  the  course  of  months. 

(c)  New  Growths. — Most  new  growths  in  the  gland  are  ade- 
noids, that  is,  tumors  that  develop  from  the  epithelial  cells  of  the 
gland;  they  have  few  blood-vessels  and  are  of  a  distinctly  defined 
nodular  nature.  As  these  nodules  grow  slowly  from  the  center 
and  have  no  tendency  to  extend  beyond  the  gland,  they  may  be 
classed  with  the  benign  tumors.  But  a  chloronia  sometimes  attacks 
the  gland,  and  is  a  very  malignant  tumor.  It  has  a  greenish  color, 
but  its  histological  structure  is  not  definitely  known.  Sarcomata  and 
carcinomata  have  been  observed."  The  first  sign  of  tumor  in  the 
lacrimal  gland  is  a  slowly  increasing  exophthalmus  that  prevents 
the  eye  from  moving  upward  and  outward.  If  the  patient  tries  to 
look  in  this  direction  (on  the  affected  side)  he  gets  cross-eyed  and 
sees  double.  Careful  examination  will  now  show  to  the  fingers  a 
hard,  lumpy  tumor,  which  may  perhaps  be  seen  under  the  conjunc- 
tiva in  the  fornix,  if  the  lid  is  everted.  If  the  tumor  increases  the 
eye   is  pushed   downward,  inward,  and  forward.       Squint  results 


I/O  DISEASES    OF   THE    LACRIMAL   APPARATUS, 

from  all  movements.  The  exophthalmus  finally  becomes  so  pro- 
nounced that  the  lids  can  no  longer  be  closed  and  lagophthalmus 
is  constant. 

Treatment  must  be  a  radical  excision,  shelling  out  the  tumor 
from  its  bed.  In  the  case  of  adenoids,  at  least,  a  permanent  cure 
may  be  expected. 

{d)  Dacryops. — The  name  is  intended  to  indicate  that  condition 
produced  when  a  duct  of  the  gland  is  occluded.  A  space  behind 
it  becomes  filled  with  tears.  The  result  is  a  bluish,  transparent 
cyst,  in  the  upper,  outer  fold  of  the  conjunctival  sac.  As  the 
tumor  grows  the  patient  complains  of  a  feeling  of  pressure  with  a 
watering  of  the  eyes. 

Treatment  seeks  to  open  a  passage  for  the  escape  of  tears.  A 
thread  piercing  the  cyst  from  without  and  allowed  to  remain  until 
it  cuts  its  way  through,  will  accomplish  this  end. 

(e)  Fistula  of  the  Lacrimal  Gland. — A  small  opening  may 
show  itself  near  the  gland  on  the  skin,  from  which  a  watery  fluid 
(tears)  escapes.  This  fistula  may  be  the  result  of  an  injury  or  an 
operation.  Healing  may  be  induced  by  connecting  the  fistula  with 
the  conjunctival  sac,  after  which  the  opening  on  the  skin  usually 
heals  of  itself  The  operation  is  made  by  a  thread,  armed  with  a 
needle  at  each  end.  One  needle  is  introduced  into  the  fistula  and 
passed  to  the  conjunctiva;  the  second  needle  is  introduced  in  the 
same  way  at  the  side  of  the  first,  after  which  the  two  ends  are  tied 
over  the  conjunctiva.  The  suture  thus  embraces  the  portion  of 
tissue  lying  between  the  fistulous  opening  and  the  conjunctiva.  If 
this  tissue  is  destroyed  by  the  pressure  of  the  suture,  the  desired 
connection  will  be  established. 

2.  DISEASES  OF  THE  LACRIMAL  PASSAGE. 
All  diseases  of  the  lacrimal  passage  have  one  sign  in  common — 
weeping  or  epiphora.  This  is  often  the  only  symptom  ;  at  least  the 
only  symptom  that  affects  the  patient  disagreeably.  It  is,  there- 
fore, the  first,  and  in  some  cases  the  only,  requisite  of  treatment  to 
effect  a  proper  discharge  of  the  tears  into  the  nose, — a  task  in 
which  even  the  cleverest  may  fail. 

Although  weeping  is  found  with  all  diseases  of  the  lacrimal  passages,  it  is  by  no  means 
true  that  epiphora  proves  the  presence  of  some  obstacle  in  these  passages  ;  for  weeping 
may  be  only  a  reflex  symptom,  since  the  tears  may  be  so  abundantly  secreted  when  cer- 
tain endings  of  the  trigeminus  are  irritated  that  even  a  normal  duct  is  unable  to  take  care 


PUNCTA    LACRIMALIA. 


171 


of  the  flood  and  to  carry  it  all  into  the  nose.  We  have  examples  enough  of  this  in  the 
ordinary  cases  of  weeping  eyes  due  to  inflammations  of  the  conjunctiva,  cornea,  or  iris. 
Many  people  weep  on  coming  into  fresh  air,  but  this  is  no  indication  that  there  is  any  dis- 
ease of  the  eye  or  any  hindrance  to  the  passage  of  tears.  We  must  suppose  that  in  their 
case  there  is  a  pronounced  irritability  of  the  trigeminus,  for  if  the  irritation  from  wind 
and  weather  be  strong  enough  any  eye  will  weep.  A  superabundant  secretion  of  tears  is, 
at  times,  a  forerunner  of  Basedow's  disease. 

{a)  Puncta  Lacrimalia. — Any  malposition  of  the  puncta  or  of 
the  lower  punctum  alone  will  cause  the  tears  to  overflow.  This 
can  be  easily  accomplished  by  dragging  down  the  lower  lid ; 
when  this  is  done  the  punctum  no  longer  rests  upon  the  eye- 
ball or  upon  the  plica  semilunaris,  and  therefore  does  not  dip  into 
the  tear  sea.  The  tears  in  running  over  soften 
the  epithelium  of  the  lid ;  this  leads  to  eczema 
of  the  lid  and  of  the  skin  ;  the  lid  grows  thicker 
and  heavier  and  a  simple  eversion  of  the  lid  is 
turned  into  a  pronounced  ectropium.  We  have 
thus  every  reason  to  endeavor  to  nullify  the  effect 
of  malpositions  of  a  punctum.  The  best  method 
is  the  one  introduced  by  Bowman  of  slitting  open 
the  canaliculus.  This  is  done  by  a  canaliculus 
knife  {Fi^;:  6j),  as  follows  :  Draw  the  lower  lid 
downward  and  outward  (or  the  upper  lid  upward 
and  outward) ;  introduce  the  point  of  the  knife 
into  the  punctum  perpendicular  to  the  edge  of 
the  lid  and  bring  the  handle  around  till  the  blade 
is  parallel  to  this  edge ;  now  push  it  forward  till 
the  point  meets  resistance  at  the  lacrimal  bone. 
After  making  sure  that  the  blade  is  in  the  correct 
position  toward  the  eyeball,  revolve  the  knife  as  a  lever,  upward 
and  inward  for  the  lower  lid  (downward  and  inward  for  the  upper 
lid),  keeping  the  point  firmly  against  the  bone.  The  wound  is 
to  be  opened  the  next  day  with  a  sound.  This  must  be  repeatedly 
done  if  the  lower  canaliculus  has  been  slit,  since  it  has  a  marked 
tendency  to  close  up.  The  canaliculus  has  been  changed  by  this 
procedure  into  an  open  gutter,  and,  as  far  as  the  disposition  of 
tears  is  concerned,  it  is  a  matter  of  indifference  whether  they  flow 
through  a  closed  passage  or  an  open  one.  If  this  gutter  opens 
properly  toward  the  globe,  the  tears  will  still  be  carried  away 
through  it,  even  if  the  lower  lid  is  slightly  everted. 

It   is  quite  evident  that  if  the  punctum   is  stopped  up  the  tears 


65. — Canaliculus 
Knife. 


1/2  DISEASES    OF   THE    LACRIMAL    APPARATUS. 

will  not  flow  through  it.  Such  a  stoppage  maybe  due  to  a  cicatrix 
of  the  lacrimal  papilla  or  of  some  adjacent  tissue.  In  reality,  it  is 
oftener  assumed  than  found.  I  myself,  at  least,  have  most  always 
been  able,  by  using  a  good  lens,  to  find  an  opening  when  the 
naked  eye  could  see  neither  papilla  nor  punctum.  Treatment 
here,  too,  is  the  above  operation,  especially  as  the  obliteration  of 
the  punctum  (of  the  lower  lid)  is  usually  associated  with  some 
ectropium.  To  enter  the  puncture  and  to  dilate  the  canaliculus  a 
fine  conical  sound  is  used.  This  can  be  done,  of  course,  only 
when  obliteration  is  not  as  complete  as  it  is  after  a  burn  or  severe 
suppuration.  In  such  a  case  we  guess  where  the  punctum  ought 
to  be,  and  after  slicing  off  part  of  the  lid  at  this  place,  try  to  find 
some  entrance  on  the  surface  of  the  wound. 

{b)  Canaliculus. — If  the  obstacle  to  the  flow  of  tears  is  in  the 
canaliculus,  there  is  a  stenosis,  which  may  be  due  to  some  foreign 
body  from  the  conjunctival  sac,  such  as  an  eyelash,  the  wing  of 
an  insect,  a  wheat  bristle,  etc.  As  this  accident  almost  always 
attacks  the  lower  canaliculus,  it  shows  the  importance  of  this  pas- 
sage for  the  flow  of  tears.  If  a  foreign  body  still  protrudes  from 
the  punctum,  it  scratches  the  eyeball  at  every  movement  of  the 
lids,  and  produces  a  conjunctivitis  or  keratitis ;  thus  there  is  epi- 
phora from  two  causes.  Such  an  inflammation  is  cured  by  remov- 
ing the  foreign  body.  The  trouble  is  more  complicated  if  the 
occlusion  is  caused  by  the  formation  of  stone  {dacryolitJi)  in  the 
canaliculus.  There  are  often  several  stones,  varying  in  size  from  a 
millet  seed  to  half  a  pea.  We  must  always  bear  this  in  mind  when 
there  is  a  tumor  in  the  neighborhood  of  the  canaliculus,  with  epi- 
phora and  some  pain,  but  no  involvement  of  the  tear  sac.  Pressure 
on  this  tumor  will  drive  a  drop  of  mucus  or  pus  from  the  punctum. 
The  microscope  shows  such  stones  to  be  composed  principally  of 
carbonate  of  lime  and  leptothrix  threads.  Polypi,  though  very 
rare,  may  produce  the  same  phenomena.  They  may  grow  so 
luxuriantly  as  to  protrude  from  the  punctum. 

Treatment  of  stone  and  polypus  consists  in  an  operation  to  re- 
move them,  for  which  purpose  slitting  the  canaliculus  is  indispensa- 
ble to  success. 

(r)  Tear  Sac  {Catarrh  of  the  Lacrimal  Sac,  Dacryocystoblennor- 
rhea.  Dacryocystitis,  Lacrimal  Fistula,  and  Hydrops  of  the  Tear  Sac). 
— These  five  diseases  may  be  described  together,  since  they  are 
essentially  but  various  stages  of  one  and  the  same  process. 


TEAR    SAC.  173 

The  mucous  membrane  of  the  tear  sac  is  subject  to  catarrh  the  same  as  any  other 
mucous  membrane.  Considering  the  connections  between  the  conjunctiva  and  the  nose, 
and  considering  what  free  access  all  fluids  of  the  conjunctiva  have  to  the  lacrimal  sac,  it 
is  a  matter  of  wonder  that  the  latter  compared  with  the  former  is  so  seldom  attacked  by 
catarrh.  It  is  probable  that  the  thick  layer  of  pavement  epithelium  in  the  lacrimal  canals 
(Merkel)  offers  some  protecting  obstacle  to  an  advance  of  a  catarrh  from  the  conjunctiva 
into  the  lacrimal  sac  ;  at  least  we  know  that  this  epithelium  on  the  cornea  offers  much 
more  resistance  to  infection  than  does  the  thinner  epithelium  of  the  conjunctiva.  Again, 
infection  of  the  tear  sac  by  fluids  from  the  conjunctiva  is  to  a  certain  extent  prevented  by 
the  rapidity  with  which  these  fluids  pass  into  the  nose.  Experience  has  taught  that  noth- 
ing so  exposes  the  tear  sac  to  disease  as  a  stoppage  to  the  flow  of  tears  below  the  sac. 
Finally,  the  comparatively  rare  ascent  of  catarrh  from  the  nose  into  the  lacrimal  sac  may 
be  explained  by  the  narrow  ness  of  the  duct  at  its  nasal  opening,  since  any  slight  catarrhal 
swelling  of  the  adjacent  mucous  membrane  must  indeed  produce  a  complete  occlusion 
there.  It  must  be  remarked  in  passmg  that  the  great  majority  of  all  so-called  strictures 
and  stenoses  of  the  lacrimal  passages  is  due  solely  to  swelling  of  the  mucous  membrane 
or  of  isolated  patches  of  it. 

In  catarrh  of  the  lacrimal  sac  the  mucous  membrane  is  red  and 
swollen;  its  secretion,  normally  clear  and  sparse,  is  now  cloudy  and 
abundant.  This  cloudiness  is  due  to  cast-off  epithelium  and  to 
migrated  pus  cells.  Since  a  congestion  of  the  mucous  membrane 
leads  in  all  cases  to  a  still  further  narrowing  of  an  already  narrow 
entrance  into  the  passage,  the  fluid  collected  in  the  sac  is  prevented 
from  escaping ;  the  sac  is  therefore  stretched,  and  a  small  tumor 
shows  itself  The  trouble  this  condition  causes  the  patient  is 
trivial,  and  for  many  hours  of  the  day  may  pass  unnoticed,  but 
when  he  goes  into  the  open  air  or  into  a  smoky  or  dusty  room 
the  tears  begin  to  run.  If  the  swelling  of  the  sac  reaches  a  higher 
stage,  there  is  a  complaint  of  pain,  or  at  least  discomfort,  at  the 
inner  canthus.  The  congestion  may,  and  undoubtedly  often  enough 
does,  disappear  without  medical  interference.  This  is,  however, 
not  always  the  result.  Stagnant  fluid  in  the  tear  sac  is  a  splendid 
nutrient  for  bacteria,  that  are  always  present  on  the  mucous  mem- 
brane of  the  nose  and  often  on  that  of  the  eye. 

When  bacteria  develop  in  the  tear  sac,  its  contents  assumes 
another  character ;  it  becomes  pus — a  condition  called  blennor- 
rhea of  the  laci'imal  sac,  or  dacryocystobletinorrJica.  The  patient 
has  still  little  to  complain  of  beyond  weeping,  red  eyes,  some 
matter  on  the  lids  in  the  morning  when  he  wakes,  or  scabs  at 
the  inner  angle.  That  is  all !  Perhaps  for  years  he  has  had 
this  trouble,  and  comes  at  last  to  the  physician  on  account  of 
some  slight  and  insignificant  injury  to  the  cornea.  He  has  now 
the  sorrowful  task  of  telling  the  patient  that  the  sword  of  Damocles 


174  DISEASES    OF   THE    LACRIMAL   APPARATUS. 

has  been  threatening  him,  that  it  has  now  fallen,  and  that  this 
blennorrhea  may  in  a  few  days  destroy  his  eye.  The  contents  of  a 
suppurating  tear  sac  is  extremely  infectious  ;  only  a  small  wound  is 
needed,  the  slightest  injury  to  the  corneal  epithelium,  to  light  up 
one  of  the  most  dangerous  of  eye  diseases,  ulcus  serpens.  Many 
a  suppurating  keratitis,  after  cataract  operation,  has  originated  from 
a  blennorrhea  of  the  tear  sac  that  the  surgeon  had  overlooked. 

The  toxic  nature  of  this  pus  may  with  very  small  encourage- 
ment be  the  cause  of  another  disease,  abscess  of  the  lacrimal  sac, 
dacryocystitis.  Some  small  area  in  the  mucous  wall  may  ulcerate  ; 
bacteria  may  penetrate  into  the  tissue  beneath,  and  an  abscess  may 
result,  which,  like  any  other  abscess,  shows  itself  with  heat,  redness, 
swelling,  pain,  and  constitutional  distu  rbance.  Abscesses  from  other 
causes  at  the  inner  canthus  below  the  tendon  are  extremely  rare, 
and  we  may,  therefore,  boldly  assume  that  any  abscess  at  this  place 
originates  in  the  tear  sac,  especially  if  the  patient  acknowledges 
that  he  has  suffered  from  a  blennorrhea  of  the  sac,  or  if  pressure 
(which  is  very  painful)  on  the  tumor  near  the  sac  expresses  any 
pus  from  a  corresponding  punctum.  Additional  symptoms  are 
redness  of  the  skin  and  conjunctivitis.  If  the  abscess  is  left  to 
itself,  it  will  sooner  or  later  open  below  and  external  to  the  tendon 
of  the  orbicularis.  After  the  pus  finds  exit,  pain  and  fever  rapidly 
disappear.  The  exciting  disease,  the  blennorrhea,  may  heal,  and  the 
contracted  tear  sac  may  cicatrize  and  atrophy.  This  favorable 
result  is  not  the  rule,  however  ;  on  the  contrary,  a  new  pathological 
condition,  fistula  sacci  lacrimalis,  is  by  far  the  more  frequent 
outcome.  The  name  suggests  an  ulcer  on  the  skin  at  the  inner 
canthus;  it  looks  like  a  small  knob  of  spongy  granulations  ;  the 
skin  near  by  is  dark  red  ;  a  fine  opening  about  the  diameter  of  a 
hair  is  visible,  from  which  exudes  a  drop  of  matter  that  is  sucked  in 
and  out  by  every  movement  of  the  lids.  The  fistula  is  in  direct 
connection  with  the  lacrimal  passage,  generally  with  the  sac  itself. 
It  may  remain  a  lifetime,  and  is  really  a  protection  against  the 
renewal  of  a  dacryocystitis,  for  it  has  been  observed  that  after  the 
fistula  has  healed  a  dacryocystitis  may  suddenly  be  lit  up,  obviously 
because  there  is  no  longer  a  natural  passage  for  the  tears  into  the 
nose;  and  an  occlusion  of  the  fistula  means,  again,  a  stasis  with  all 
its  dire  consequences. 

Many  a  patient  has  a  suppurating  tear  sac  for  years  without 
infecting  the  conjunctiva  or  cornea.     Gradually,  too,  the  contents 


TEAR   SAC.  175 

of  the  sac  ceases  to  be  pus  and  becomes  watery  and  thin.  The 
mucous  membrane  is  no  longer  thick,  velvety,  and  red,  but  is  thin, 
pale,  and  slate  colored.  As  it  shrinks,  the  mucous  membrane  loses 
its  resistive  power,  and  fluid  collecting  within  the  sac  stretches  it 
more  and  more  to  the  size  of  a  pea,  or  even  of  a  cherry.  As  it  is 
certain  to  be  stretched  in  the  direction  of  least  resistance,  toward 
the  skin,  the  result  is  a  tumor  visible  externally,  with  well-defined 
outline,  because  there  is  now  no  inflammatory  infiltrate  in  the 
adjacent  skin.  This  condition  is  called  Hydrops  sacci  lacrimalis. 
It  may  appear  and  disappear,  or  remain  permanently,  although  at 
times  the  mucous  membrane  of  the  lacrimal  duct  may  so  retract  as 
to  open  a  passage  for  the  tears  into  the  nose.  It  seems  that  if  the 
sac  is  once  stretched  beyond  a  certain  limit,  the  lids  lose  their 
effectiveness  as  a  pump,  and  that  the  filled  or  even  over-filled  sac 
can  be  emptied  only  by  pressure  of  the  finger,  even  if  the  passage 
to  the  nose  is  still  patent. 

From  the  symptoms  and  signs  given  it  ought  to  be  easy  to 
recognize  these  five  diseased  conditions.  Dacryocystitis  and  fis- 
tula need  only  to  be  seen  to  be  diagnosticated.  A  simple  catarrh, 
a  blennorrhea,  or  a  hydrops  are  discovered  by  the  trick  of  emptying 
the  sac  with  pressure  of  the  finger,  but  to  be  successful  one  must 
keep  the  puncta  lacrimalia  constantly  in  view.  The  best  way  is  to 
stretch  the  lids  with  one  hand,  at  the  same  time  ectropionizing  them 
somewhat,  while  a  finger  of  the  other  hand  is  firmly  pressed  upon 
the  inner  tendon  or  the  orbicularis.  In  catarrh,  a  watery,  floccu- 
lent  fluid  gushes  out,  in  blennorrhea  there  is  more  or  less  pus,  but  in 
hydrops  there  may  be  nothing,  as  all  the  fluid  may  escape  into  the 
nose.  From  a  normal  lacrimal  sac  nothing  can  be  expressed,  that 
is,  nothing  upon  the  conjunctiva. 

Treatment  of  catarrh  and  of  blennorrhea  must  be  begun  by  a 
radical  examination  of  the  nasal  mucous  membrane,  as  not  only 
may  catarrh  arise  from  this  source,  but  there  is  always  danger  of  a 
tuberculous  infection  of  the  lacrimal  passage.  I  cannot  here  dis- 
cuss the  treatment  of  the  nasal  mucous  membrane ;  that  of  the  tear 
sac  must  first  attempt  to  secure  a  free  passage  into  the  nose,  and 
second  to  restore  the  mucous  membrane  to  its  normal  condition. 
If  the  first  succeeds,  the  second  will  generally  be  accomplished  of 
itself,  because,  as  has  been  mentioned,  a  catarrh  or  a  blennorrhea  is 
due  to  occlusion  of  the  lacrimal  passage  into  the  nose.  The  oc- 
cluded canal  is  opened  by  means  of  Bowman's  cylindrical  sound 


176 


DISEASES    OF    THE    LACRIMAL   APPARATUS 


{Fig.  6y)  or  of  Weber's  cone-shaped  sound  {Fig.  66).  Now  slit  the 
upper  canaliculus,  since  this  is  the  shorter,  has  less  tendency  to 
close  again,  and  is  easier  to  sound  than  is  the  lower  one.  The 
proceeding  is  moderately  painful,  but  this  may  be  diminished  by  a 
few  drops  of  a  5  per  cent,  solution  of  cocain  on  the  conjunctiva. 
The  next  day  the  lips  of  the  wound  are  to  be  opened  by  a  sound 
and  at  the  same  time  an  attempt  should  be  made  to  pass  it  carefully 


Fig.  66. — Weber's  Sound. 


Fig.  67. — Bowman's  Sound. 


further  on.  In  doing  this,  the  upper  lid  must  be  firmly  drawn 
outward  and  upward ;  the  point  of  the  sound  is  passed  along  the 
back  of  the  incision  in  the  canaliculus  to  the  nose  until  it  is  felt  to 
strike  against  a  bony  resistance  ;  the  sound  is  then  rotated  till  it 
points  in  a  downward  direction,  which  will  be  given  it  by  holding 
the  point  against  the  lacrimal  bone.  An  effort  should  now  be 
made  to  pass  the  sound  into  the  nasal  duct,  pushing  it  along  the 


TEAR    SAC.  177 

inner,  bony  wall  of  the  sac.  If  the  sound  is  in  the  proper  position, 
that  is,  if  it  lies  in  the  sagittal  suture,  between  the  nasal  bone  and 
the  tear  sac,  the  effort  will  be  successful  with  only  moderate  force. 
Once  in  the  duct,  the  greatest  difficulty  is  overcome,  even  if  a  few 
narrow  places  demand  a  stronger  pressure  to  pass  them.  The 
amount  of  pressure  necessary  can  be  judged  only  by  experience. 

The  following  rules  must  be  observed  :  Bone-like  resistance  indicates  a  false  passage,  as 
the  resistance  offered  by  a  fold  of  swollen  mucous  membrane  always  yields  in  some  degree. 
If  no  advance  can  be  made,  the  sound  should  not  be  pushed  to  the  right  or  left,  but 
must  be  withdrawn  a  few  millimeters  and  again  pushed  forward.  If  this  is  not  successful, 
try  another  sound  ;  thicker  ones  often  pass  where  thin  ones  have  been  caught,  for  the 
smoothed-out  folds  in  the  membrane  that  offer  an  obstacle  to  thin  sounds  may  be  no 
hindrance  to  thicker  ones.  If  they  all  fail,  wait  a  few  days  before  making  the  next 
attempt.  By  that  time  the  mucous  membrane  may  have  shrunken  so  materially  as  to 
simplify  the  passage  of  a  sound.  The  first  introduction  of  a  sound  is  extremely  painful, 
the  pain  radiating  to  the  teeth  ;  some  patients  even  faint.  Repeated  applications  of  co- 
cain  to  the  conjunctiva  may  lessen  the  pain  considerably.  Hemorrhage  is  not  uncommon. 
It  indicates  the  necessity  for  great  care,  small-sized  sounds,  and  longer  intervals  between 
each  effort. 

The  more  experience  I  have  the  less  eager  I  am  to  begin  the  use  of  the  sound.  I 
have  given  up  entirely  the  larger  sounds.  It  has  often  been  my  misfortune  to  see  an  open 
lacrimal  passage  gradually  grow  narrow  and  narrower,  pari  passu  with  the  treatment  by 
the  sound,  and  finally  to  become  quite  impervious,  presumably  on  account  of  a  periostitis 
due  to  this  sounding  of  the  lacrimal  duct. 

If  the  sound  is  successfully  passed,  it  should  remain  two  to  twenty 
minutes  according  to  the  difficulty  found  in  passing  it.  If  it  went 
in  easily  and  if  the  duct  was  narrow  at  only  certain  places,  say  at 
the  beginning  and  end,  the  sound  can  remain  twenty  minutes.  But  if 
the  whole  canal  was  narrow  and  tight,  the  sound  should  be  taken 
out  at  once,  otherwise  it  will  in  a  few  minutes  be  so  tightly  grasped 
by  the  stricture  that  considerable  strength  will  be  needed  to  remove 
it,  and  even  then  hemorrhage  may  be  caused.  As  a  rule,  weeks  or 
months  will  be  consumed  before  the  patient  can  be  discharged. 
Probing  must  be  continued  at  intervals  of  four  to  eight  days  until 
the  higher  number,  j  (Bowman),  can  be  easily  introduced  at  any 
time.  I  do  not  even  then  dismiss  my  patients,  but  advise  them  to 
return  every  fourteen  days  for  the  sound,  and  finally  every  month ; 
relapses  may  be  thus  avoided. 

The  slow  results  of  the  use  of  the  sound  induced  .Stilling  to  try  '*  Stricttirotomy^'' 
that  is,  cutting  open  the  stricture  by  means  of  a  small  knife  especially  constructed  for 
entering  the  nasal  duct  through  the  lacrimal  sac.  Thomas  has  recently  recommended 
the  operation  warmly.  Fig.  68  shows  the  knife  used  by  him.  It  can  obviously  be  used 
only  in  the  cases  in  which  the  blunt  point  of  the  knife  will  first  pass  the  stricture. 
12 


1/8 


DISEASES    OF   THE    LACRIMAL   APPARATUS. 


Stilling  omitted  further  local  treatment ;  Thomas,  on  the  other  hand,  held  it  necessary 
to  have  the  patient  carry  a  lead  sound  of  about  /.j"  mm.  diameter  for  some  time  after  the 
operation.  It  must  be  confessed  that  this  method  has  cured  cases  pronounced  incurable 
by  the  ordinary  use  of  sounds. 

The  fact  that  a  sound  if  long  retained  is  held  fast,  due  obviously  to  the  swelling  of  the 
mucous  membrane,  suggested  to  me  to  try  a  method  that  might  be  called  "  graduated 
sounding."  At  first  a  thin  sound  is  introduced  well  anointed  with  cocain  salve,  and  is  then 
moved  back  and  forth  in  the  nasal  duct  till  it  passes  with  noticeable  ease.  It  is  now  drawn 
out  and  a  thicker  one  introduced,  moved  back  and  forth  till  it  also  meets  no  resistance. 
I  have  had  the  good  luck  in  the  very  first  sitting  to  be  able  thus  to  introduce  with  no 
difficulty  at  all  the  thickest  sound  I  ever  use. 


Fig.  68. — Knife  for  Cutting 
A  Stricture  of  the  Nasal 
Duct. 


Fig.   6g  — Syringe  for   Injecting  thf. 
Lacrimal  Passages. 


For  direct  effect  upon  the  mucous  membrane  we  use  various 
solutions  injected  into  the  tear  sac  by  a  suitable  syringe  {Fig.  dp). 
If  the  passage  is  pervious,  most  of  the  fluid  runs  into  the  nose,  and 
from  there  either  out  of  the  nostrils,  or,  if  the  patient  throws  his 
head  back,  into  the  throat. 

The  solutions  most  generally  applied  are  0.6  per  cent,  sjtlfate  of 
zinc,  I  per  cent,  acetate  of  lead,  2  to  j  per  cent,  nitrate  of  silver,  i  to  2 
per  ce7it.  tannic  acid,  0.02  per  cent,  corrosive  sublimate,  and,  finally, 
iodoform  emulsion.     I  have  seen  the  best  results  from  nitrate  of 


TEAR    SAC.  179 

silver.     There  are  cases  enough,  however,  where  suppuration  will 
not  dry  up  in  spite  of  all  possible  fluid  applications. 

Under  these  circumstances  I  have  felt  justified  in  daring  to  use  a  solution  of  10  per 
cent,  chlorid  of  zinc.  The  result  was  unexpectedly  favorable.  In  many  cases  a  single 
injection  was  sufficient  to  stop  completely,  and  finally  to  dry  up,  all  suppuration.  Of 
course,  such  a  fearful  means  of  cautery  can  be  attempted  only  under  certain  precautions. 
The  best  plan  is  the  following  :  first  inject  several  drops  of  a  five  per  cent,  cocain  solution 
into  the  tear  sac  to  reduce  the  pain  as  much  as  possible,  when  the  whole  conjunctiva  and 
cornea  is  covered  with  a  thick  protective  layer  of  vaselin.  Now  the  surgeon  can  inject 
several  drops  of  the  10  per  cent,  chlorid  of  zinc  into  one  punctum  or  canaliculus,  while 
an  assistant  injects  into  the  other  punctum  a  four  per  cent,  solution  of  carbonate  of  soda. 
The  chlorid  of  zinc,  as  it  flows  back,  unites  with  the  carbonate  of  soda  to  form  chlorid  of 
soda  and  carbonate  of  zinc,  two  indifferent  and  unirritating  solutions.  The  reaction  to  the 
chlorid  of  zinc  solution  is  very  intense ;  it  is  best,  therefore,  to  tell  the  patient  that  his 
face  will  puff  up  somewhat,  but  that  this  puffiness,  with  any  pain  accompanying  it,  will 
disappear  after  a  few  hours  if  he  use  hot  compresses.  I  happened  quite  accidentally  upon 
this  plan,  which  has  already  been  tried  by  other  surgeons.  While  sitting  one  day  with  a 
few  colleagues,  we  began  to  confess  our  ophthalmic  sins.  One  of  us  said  that  he  had 
once  picked  up  the  wrong  bottle,  and  had  in  consequence  injected  the  ten  per  cent, 
chlorid  of  zinc  instead  of  0.02  per  cent,  sublimate  solution  into  the  tear  sac.  The  whole 
face  had  swollen  up  dreadfully,  but  the  suppuration  had  stopped  then  and  there. 

It  is  evident  that  suppuration  will  not  cease  if  the  passage  for 
the  tears  into  the  nose  cannot  be  kept  open.  Therefore,  if  the  pa- 
tient is  to  be  freed  from  the  danger  constantly  threatening  when 
there  is  pus  in  the  neighborhood  of  the  noble  organ  of  vision, 
nothing  remains  but  to  extirpate  or  to  destroy  the  lacrimal  sac. 
To  cut  out  the  tear  sac  uninjured  is  an  operation  more  often  begun 
than  carried  out  according  to  program.  Arlt,  that  past  master  of 
operative  ophthalmology,  gave  up  the  method  after  several  attempts. 
If  the  operation  is  decided  upon,  it  is  best  in  every  case  to  have 
ready  knife,  scissors,  forceps,  chisel,  with  other  appliances  and  a 
sharp  spoon  to  scrape  away  bits  of  mucous  membrane  or  other  im- 
peding tissue,  in  case  of  severe  hemorrhage,  thus  transforming  the 
operation  into  a  curetting  one  instead  of  a  literal  extirpation. 

The  obliteration  of  the  tear  sac  is  a  classical  method,  and  was 
done  by  the  actual  cautery  or  by  various  chemicals.  It  is  to-day 
effected  as  follows :  after  anesthetizing  the  patient,  the  lids  are 
drawn  firmly  outward  and  the  point  of  a  knife  is  entered  just  below 
the  prominence  of  the  tendon  of  the  orbicularis,  pushed  on  into 
the  tear  sac,  and  then  withdrawn  in  a  downward  direction,  cutting 
through  with  one  stroke  the  anterior  wall  of  the  sac,  the  subcuta- 
neous tissue,  and  the  skin ;  the  incision  is  then  widened  upward 
through  the  tendon  to  include  the  fundus  of  the  sac.     The  wound 


l8o  DISEASES    OF    THE    LACRIMAL   APPARATUS. 

is  now  held  open  by  two  forceps  or  sharp  hooks,  and  after  stopping 
hemorrhage,  so  as  to  get  a  good  view  of  the  mucous  membrane,  it 
is  thoroughly  cauterized  by  the  galvano-cautery. 

It  may  be  mentioned  that  v.  Wecker  rejected  this  destruction  of  the  tear  sac  and  re- 
placed it  by  his  method  of  making  a  large  opening  for  the  tear  sac  into  the  conjunctival 
sac,  combined  with  extirpation  of  the  lacrimal  gland.  What  good  does  all  this  do,  if  in 
spite  of  it  the  mucous  membrane  of  the  tear  sac  continues  to  suppurate  ? 

Treatment  of  abscess,  fistula,  and  hydrops  of  the  lacrimal  sac 
needs  further  mention.  Abscess  must  be  opened  as  early  and  as 
thoroughly  as  possible.  This  may  occasionally  be  effected  by  slit- 
ting the  canaliculus,  but  usually  an  incision  through  the  skin  and 
anterior  wall  of  the  sac  cannot  be  avoided.  After  the  abscess  heals 
there  still  remains  the  hard  task  of  curing  the  blenorrhea. 

To  cure  a  fistula  we  must  first  try  to  restore  the  normal  passage. 
If  this  is  done,  the  fistula  will,  as  a  rule,  heal  of  itself,  or  may  be 
encouraged  to  do  so  by  applications  of  nitrate  of  silver  or  tincture 
of  iodin. 

In  hydrops  we  have  the  choice  between  incision  through  the  an- 
terior wall  of  the  sac  or  its  obliteration — assuming  that  the  patient 
spares  us  the  trouble  of  choosing  by  insisting  that  he  is  quite  con- 
tent with  his  present  condition  and  refusing  any  operative  inter- 
ference. 

{d')  Nasal  Duct. — It  has  already  been  said  that  disease  of  the 
nasal  duct  is  one  of  the  most  prominent  sources  of  infection  in  the 
lacrimal  sac.  The  commonest  cause  of  disease  in  the  nasal  duct  is 
a  catarrh  of  the  nasal  mucous  membrane,  which,  when  congested, 
affects  the  entrance  of  the  duct  and  causes  a  stenosis.  The  intro- 
duction of  the  sound,  used  in  the  interest  of  the  tear  sac,  overcomes 
the  stenosis  and  therefore  heals  the  catarrh.  If  it  seems  best  to 
treat  the  mucous  membrane  especially,  a  good  device  for  that 
purpose  is  the  hollow,  perforated  sound  of  v.  Wecker,  through 
which  fluids  may  be  injected  upon  any  area  of  the  passage. 

In  rare  cases  the  whole  passage  is  absolutely  impassable,  and 
successful  local  treatment  seems,  therefore,  out  of  the  question.  As 
causes  of  such  an  occlusion  may  be  mentioned  foreign  bodies,  so- 
called  dacryoliths,  new  growths  of  the  adjacent  tissue, — especially 
those  of  the  nasal  cavities, — and  affections  of  the  canal  due  to 
injuries,  lupus,  syphilis,  and  tuberculosis  (caries)  of  the  bones. 

Assuming  that  the  dacryostenosis  is  not  altogether  subordinate  to 
the  general  disease,  operative  measures  may  be  suggested,  depend- 


ANATOMY    OF   THE    CONJUNCTIVA. 


i8i 


ent  on  the  presence  or  absence  of  pus  in  the  lacrimal  sac.  If  there 
is  pus,  the  old  barbarous  method  of  forcing  a  new  passage  through 
the  lacrimal  bone  into  the  nose  need  not  be  thought  of,  but  the 
surgeon  can  content  himself  with  the  treatment  by  ten  per  cent, 
chlorid  of  zinc,  or  with  obliteration  of  the  sac. 


III.  DISEASES  OF  THE  CONJUNCTIVA. 

Anatomical  and  General  Remai-ks. — If  the  lids  are  shut,  tlie  conjunctiva  forms  a  closed 
sac  {^Fig.  j6)  whose  walls  are  pressed  against  each  other  by  the  protrusion  of  the  eyeball 
from  behind  (the  anterior  layers  of  the  cornea,  the  epithelium,  and  Bowman's  mem- 
brane being  considered  a  part  of  the  conjunctiva,  the  conjunctiva  corneir).     That  part  of 


TornyC'  ceri/tuictiva^. 


Gm/u/vctit'a- 


Om/u/ictiynpa^fehrge 
•superiors 


buZbl 


Fir..  70. 

Conjunctival  sac  (in  heavy  black)  is  in  reality  only  a  capillary  fissure,  but  here  it  is  exaggerated  for  the 

sake  of  clearness.     {After  Merkel.) 


the  conjunctiva  covering  the  back  of  the  lid  is  called  conjunctiva  palpebrarum ;  that 
covering  the  anterior  segment  of  the  globe  is  called  conjunctiva  sclera,  or  bulbi ;  that 
part  forming  the  fold  between  the  two  is  called  fornix  conjunctivcv.  The  histological 
structure  is  quite  different  in  these  three  divisions,  but  they  all  have  in  common  an  epi- 
thelium, a  substantia  propria,  and  a  subconjunctival  connective  tissue. 

The  conjuttcfiva  palpebrarum  (compare  Pig.  J7,  /.  143)  forms  in  the  vicinity  of  the 
palpebral  fissure  a  smooth  covering  for  the  tarsus;  further  back,  at  that  edge  of  the  tarsus 
away  from  the  fissure,  the  conjunctiva  becomes  thick,  pitted,  uneven.  If  looked  at  with 
a  lens,  it  is  seen  to  be  covered  with  fine  papillre,  a  fact  that  suggested  the  idea  of  a  papil- 
lary body  [Fig.  jy).  The  epithelium  is  conijXjsed  of  cylindrical  cells  on  the  surface, 
with  a  layer  of  round  cells  beneath  them.  The  tunica  propria  consists  of  a  thick  con- 
nective tissue  of  few  elastic  fibers  in  which  numerous  lymph  bodies  are  sprinkled ;  on 
account  of  these  latter  it  has  been  called  "  adenoid."  These  lymph  nodules  are  particu- 
larly abundant  in  the  "  papillary  body."  The  tarsus  (Fig.  jy)  in  the  conjunctiva  of  the 
lid  takes  the  place  of  the  subconjunctival  connective  tissue. 


l82  DISEASES    OF    THE    CONJUNCTIVA, 

At  the  fornix  the  conjunctiva  leaves  the  lids  abruptly,  but  passes  much  more  gradu- 
ally onto  the  globe.  There  are  here  three  or  four  layers  of  epithelial  cells.  The  tunica 
propria  cannot  be  separated  from  the  subconjunctival  tissue,  but  both  of  these  layers,  by 
having  a  more  me.sh-like  structure  and  an  abundance  of  elastic  fibers,  are  different  from 
the  corresponding  layers  of  the  palpebral  conjunctiva.  Lymph  nodules  are  found  in  clus- 
ters at  the  fornix,  the  so-called  "  leukocyte  follicles,"  cell  masses  enclosed  in  an  un- 
doubted connective-tissue  capsule.  Many  histologists  declare  that  these  lymph  follicles 
are  in  man  always  pathological.  We  shall  learn  that  in  certain  diseases  of  the  conjunc- 
tiva they  have  an  important  part  to  play. 

On  the  conjunctiva  bulbi  the  epithelium  becomes  richer  in  cells  as  we  approach  the 
cornea,  and  possesses  peculiar  goblet  cells  (individual  mucous  glands).  ^  The  tunica 
propria  and  the  subconjunctival  tissue  are  like  that  of  the  fornix  in  construction,  and  are 
loosely  connected  by  a  few  fibers  with  the  sclera  and  the  tendons  of  the  eye  muscles  ;  this 
connection  is  especially  intimate  along  the  "  scleral  border,"  that  is,  at  the  circle  of  union 
between  sclera  and  cornea.  The  epithelium  passes  without  interruption  into  that  of  the 
cornea,  while  the  connective  tissue  becomes  Bowman's  membrane  (^Fig.  4, p.  2j).  Par- 
ticular notice  must  be  given  to  the  blood-vessels  of  the  conjunctiva.  On  the  lid  they  are 
thin,  and  run  parallel  to  each  other  from  the  fornix  to  the  lid's  edge  ;  the  conjunctiva  of 
the  globe  and  of  the  fornix  have,  on  the  other  hand,  a  network  of  stronger  vessels  that 
spread  in  all  directions  like  the  branches  of  a  tree.  As  a  result  of  the  structure  of  the 
tunica  propria  in  various  places,  it  will  be  noticed  that  the  conjunctiva  of  the  lid  cannot 
be  moved,  while  on  the  globe  it  is  easily  displaceable. 

The  anatomical  subdivision  of  the  conjunctiva  into  three  parts  gives  us  a  certain  nat- 
ural subdivision  for  pathological  study.      That  is  to  say — 

(1)  The  diffuse  inflammations  attack  particularly  the  conjunctiva  of  the  lid. 

(2)  The  diseases  characterized  by  the  growth  of  follicles  and  granulations  attack  the 
fornix;  and 

(3)  77/1*  localized  (focus)  diseases,  as  phlyctenules,  pterygia,  xerosis,  attack  the  conjunc- 
tiva of  the  globe. 

If  the  conjunctiva  is  inflamed  the  eye  looks  red,  but  every  red  eye  does  not  have  an 
inflamed  conjunctiva.  As  it  is  transparent,  one  can  see  through  the  conjunctiva  the 
deeper  congested  blood-vessels.  There  are  three  ways  of  distinguishing  deep  from  super- 
ficial injection  : — 

(i)  Vessels  lying  in  the  conjunctiva  are  easily  movable  upon  the  sclera  beneath  it. 

(2)  Individual  vessels  are  bright  red  ;  and 

(3)  They  can  be  traced  along  their  entire  course. 

In  a  deeper  injection  single  vessels  cannot  be  seen,  and  there  is  only  a  diffused  and 
bluish-red  color,  which  passes  from  delicate  rose  to  a  light  purple,  according  to  the  depth 
of  the  injection.      The  sclera  when  injected  appears  violet. 

To  recognize  diseases  of  the  conjunctiva,  it  is  necessary  to  examine  it  throughout  its 
entire  extent.  Sometimes  this  is  easy,  sometimes  hard,  occasionally  impossible,  according 
to  the  stiffness  of  the  lids,  the  amount  of  pain  present,  and  the  good  or  bad  intention  of 
the  patient.  The  conjunctiva  of  the  lower  lid,  of  the  fornix,  and  of  the  lower  half  of  the 
eyeball  is  visible  if  the  surgeon  places  his  finger  at  the  edge  of  the  lid,  presses  it  firmly 
downward,  and  asks  the  patient  to  look  upward.  A  patient  with  any  painful  affection 
and  dread  of  light  does  this  instinctively.  The  task  is  more  diflicult  in  the  case  of  the 
upper  lid.     The  patient  is  asked  to  look  toward  the  ground,  because  the  upper  lid  is  thus 

^  Many  observers  maintain  that  this  is  a  mucous  degeneration  of  the  epithelium  and  is 
pathological . 


HYPEREMIA  ACUTA — HYPEREMIA  CHRONICA.         I  83 

best  flattened  out.  Then  the  surgeon  grasps  a  few  lashes  between  the  left  index  finger 
and  thumb,  and  pulls  firmly  downward  and  outward  so  as  to  draw  the  lid  away  from  the 
eyeball ;  at  the  same  time  he  presses  with  the  thumb  of  the  right  hand  against  the  upper 
edge  of  the  tarsus  and  pushes  it  firmly  downward,  while  the  left  hand  pulls  the  lid 
upward,  the  right  thumb  nail  supplying  the  fixed  point  about  which  the  lid  is  revolved. 
It  is  easier  for  the  beginner  if  he  uses  in  place  of  the  right  thumb  a  stiff  sound  or  a  glass 
rod,  placed  horizontal  at  the  upper  edge  of  the  tarsus  ;  it  may  be  withdrawn  as  soon  as 
the  lid  is  turned  over.  The  patient  does  not  always  obey  the  order  to  look  downward ; 
sometimes  the  lashes  cannot  be  grasped  because  they  are  too  short  or  too  scanty.  In 
such  cases  draw  up  the  skin  on  the  lid  with  the  index  finger  of  the  left  hand,  so  as  to 
show  the  posterior  edge  of  the  lid,  then  push  the  left  thumb  beneath  it,  and  press  it  firmly 
upward,  while  the  right  hand  does  its  part  as  above  described.  To  get  a  view  of  the 
fornix,  the  ectropionized  lid  must  be  lifted  from  the  globe  by  a  sound  or  a  spatula,  or  it 
can  be  turned  over  a  second  time  if  the  patient  will  continue  to  look  downward  with  all 
his  might. 

I.  DIFFUSE  INFLAMMATIONS. 

(a)  Hyperemia  acuta. — In  the  strict  sense  of  the  word,  hypere- 
mia, that  is,  a  fulness  and  congestion  of  the  blood-vessels  of  the 
conjunctiva,  is  not  a  disease  but  a  symptom,  introducing  a  series 
of  different  diseases  ;  but  it  is  often  the  only  symptom  and  to  this 
extent  it  is  the  disease  itself.  This  is  the  case,  for  example,  when 
a  foreign  body  remains  in  the  conjunctival  sac  ;  it  then  produces  a 
feeling  of  something  in  the  eye,  with  pain,  fear  of  light,  vascular  in- 
jection, weeping,  and  even  spasms  of  the  lids,  which  may  continue 
after  it  has  been  removed.  It  happens,  therefore,  that  a  patient 
sometimes  presents  himself  with  a  pure  hyperemia.  The  conjunc- 
tiva looks  bright  red  and  shiny  and  is  somewhat  swollen  by  trans- 
uded serum.  It  is  oftener  the  case  that  the  cause  of  the  hyperemia 
is  still  there,  whether  this  be  the  first  expression  of  a  beginning 
conjunctival  inflammation,  or  a  foreign  body,  or  a  wild  hair  (p. 
i^j)  still  scratching  the  eye.  It  is  therefore  essential,  when  a 
patient  with  red  eyes  is  seen,  always  to  examine  the  lashes  and  to 
scrutinize  the  entire  conjunctiva  for  foreign  bodies. 

Treatment  of  a  pure  hyperemia — beyond  removal  of  the  cause, 
a  foreign  body  or  a  displaced  eyelash — is  unimportant ;  the  red- 
ness with  all  other  signs  of  irritation  disappears  in  a  few  hours. 

{d)  Hyperemia  chronica  {Catarrhus  siccus.  Dry  Catarrh). — The 
patient  complains  of  all  sorts  of  uncomfortable  sensations  in  the 
eye,  prickling,  itching,  foreign  body,  heavy  upper  lids,  and  frequent 
winking.  The  distress  increases  toward  evening  and  after  use,  and 
bears  no  relation  to  the  pathological  change  in  the  conjunctiva 
itself.     Moderate  alterations  in  the  tissue  may  produce  severe  dis- 


184  DISEASES    OF   THE    CONJUNCTIVA. 

comfort  in  case  the  lids  cling  to  the  eyeball ;  gross  alterations  are 
borne  surprisingly  well  if  the  lids  can  be  opened  wide  and  are  re- 
laxed. This  is  true  of  all  other  diseases  of  the  conjunctiva.  In 
cases  of  dry  catarrh,  there  is,  as  a  rule,  very  little  to  see  by  merely 
looking  at  the  patient,  but  if  we  examine  the  conjunctiva  on  the 
lids  and  at  the  fornix  we  notice  that  they  are  redder  and  rougher 
than  normal.  The  inner  surface  of  a  normal  lid,  when  inverted,  is 
yellow  and  has  numerous  fine  but  plainly  marked  vessels  running 
from  the  fornix  to  the  edge  of  the  lid,  while  a  catarrhal  condition 
is  evidenced  by  a  uniform  redness,  and  along  the  upper  edge  of  the 
tarsus,  particularly  at  the  sides,  it  seems  covered  with  small  nodules 
of  raw  flesh.  These  nodules  appear  to  the  naked  eye  like  the  nor- 
mal conjunctiva  looked  at  through  a  magnifying  glass.  This 
redness  and  roughness  or  uneven  congestion  is  most  strongly 
developed  in  the  papillary  body,  and  diminishes  rapidly  from  the 
fornix  toward  the  free  edge  of  the  lid.  There  is  no  pathological 
secretion. 

The  causes  of  dry  catarrh  are  manifold.  The  most  common  is 
irritation  by  dust  and  similar  foreign  substances,  and  for  that  reason 
millers,  stone  masons,  innkeepers,  school  children,  and  prisoners 
are  most  exposed  to  the  disease.  Lithiasis  palpebrarum  (/>.  1^6) 
may  be  added  to  this  group. 

A  second  group  of  causes  is  found  in  the  different  conditions 
that  hinder  regular  flow  of  tears  (/>.  lyo  et  seg.).  If  the  eye  is  con- 
stantly bathed  in  tears,  it  encourages  all  harmful  influences,  and  but 
affirms  the  proverb  of  a  classical  teacher  of  ophthalmology  that 
"  tears  are  the  eyes'  worst  enemy." 

Finally,  there  is  always  the  possibility  that  a  dry  catarrh  is  but  a 
disease  inseparable  from  certain  occupations.  For  example,  fire- 
men and  puddlers  who  must  work  in  a  fierce  light,  or  students  who 
for  hours  at  a  time  read  and  write  by  artificial  light,  expose  them- 
selves to  the  dangers  of  a  conjunctival  (or  retinal)  hyperemia. 
To  be  sure,  the  eyes  most  endangered  by  such  occupations  are 
those  already  burdened  with  some  pathological  condition,  such  as 
hyperopia,  astigmatism,  or  insufficiency  of  the  internal  recti 
muscles. 

Treatment,  in  all  cases  due  to  the  latter  cause,  must  begin  with 
the  prescription  of  the  proper  glasses.  In  diseases  of  the  lacrimal 
passages  the  methods  mentioned  on  /.  770  ct  scq.  must  be  resorted 
to.     If  the  irritation  is  due  to   strong  light   or  to   dust,  protective 


CONTUNCTIVITIS    CATARKHALIS   SIMPLEX. 


i8; 


smoke  glasses  can  be  advised.  If  the  catarrh  continues  in  spite 
of  the  removal  of  the  cause,  or  if  the  cause  cannot  be  removed,  as 
will  probably  be  the  case  when  it  is  one  of  the  first  group, 
astringent  applications  and  the  eye  douches  are  of  service.  I 
usually  commence  by  flooding  the  conjunctival  sac  twice  daily 
with  zinc  washes  {Zinc  Sidph.  0.2,  Aqiue  dist.  jo.o).  In  case  this 
does  not  accomplish  the  purpose,  I  apply  every  second  day  to  the 
inner  surface  of  the  lids  a  two  per  cent,  solution  of  silver  nitrate. 
A  drop  of  tincture  of  opium  once  a  day  or  every  second  day  has 
been  recommended.^  Besides  these  applications,  which  all  irritate 
for  the  moment,  we  can  use  the  eye  douche  {Fi£^.  7/),  which  is 
immediately  soothing.  A  rather  powerful  stream  of  lukewarm 
and  later  cold  water  is  allowed  to  flow  from  three  to  five  minutes 
against  the  closed  lids,  twice  a  day. 

{c)  Conjunctivitis  catarrhalis  simplex 
{Simple  Catarrh). — This  begins  with  hypere- 
mia, redness,  and  an  irregular  congestion  of 
the  mucous  membrane,  to  which  a  profuse 
discharge  is  soon  added.  This  discharge 
consists  at  first  of  a  watery,  slightly  cloudy, 
sticky  fluid,  in  which  a  few  mucous  particles 
float.  It  becomes  gradually  richer  in  cells, 
cloudier,  and  more  abundantly  supplied  with 
fibrinous  matter  that  changes  to  pus  at  the 

height  of  the  disease.  Since  such  a  fluid  does  not  easily  flow 
through  the  lacrimal  passages,  the  mucus  and  pus  collect  at  the 
inner  canthus  and  on  the  lids,  and  the  lashes  are  matted  together 
in  masses.  As  there  are  more  tears  than  normal,  the  lids  and 
edges  are  kept  constantly  moist,  this  sufficing  in  scrofulous , 
children  or  those  with  tender  skin  to  produce  a  blepharitis  (/.  /^p) 
or  an  eczema  (/.  144)  of  the  lid. 

The  tears  dry  up  during  sleep,  and  the  secretion  collected  along 
the  lids  dries  also  into  hard  crusts  that  stick  the  lids  firmly  together. 
The  hyperemia  of  the  conjunctival  vessels  is  extreme  and  general. 
Even  the  intermarginal  portion  of  the  lids  and  the  conjunctiva  bulbi 


Fig. 


— Eve  Douche. 


^  I  have  given  up  touching  very  swollen  lids  with  blue  stone  (Cuprum  sulfuricum),  as 
it  seemed  to  me  that  the  conjunctiva  became  smoother  but  not  thinner  nor  paler.  Some 
surgeons  recommend  acetate  of  lead  0.2  per  cent,  to  0.3  per  cent.,  others,  aluminate  of 
copper  0.2  per  cent,  to  0.3  per  cent. ,  or  borate  of  soda  0.25  per  cent,  to  0.5  per  cent. ,  or 
compresses  of  sublimate  solution  0.05  to  water  200.0. 


1 86  DISEASES    OF    THE    CONJUNCTIVA. 

below  the  fissure  are  congested,  this  being  particularly  the  case  at 
the  caruncles  and  adjacent  parts.  At  the  fornix  and  on  the  lids 
this  hyperemia  is  most  pronounced.  Even  when  the  lids  are 
everted  and  the  conjunctiva  thereby  put  on  the  stretch,  the  tarsus 
is  invisible,  for  the  conjunctiva  is  so  filled  with  blood  and  saturated 
with  exudate  that  it  is  no  longer  transparent.  The  cornea  remains 
healthy  as  a  rule,  and  only  in  old  persons  do  we  see  a  loss  of  epi- 
thelium and  corneal  ulcers  resulting  from  it. 

If  the  disease  is  left  to  itself  it  subsides  within  one  to  three  weeks. 
The  secretion  lessens,  and  hyperemia  and  congestion  of  the  con- 
junctiva disappear  in  some  portions,  particularly  in  those  near  the 
fornix.  The  conjunctiva  here  appears  red,  velvety,  and  rough,  as  if 
strewn  with  "  papillae."  This  is  the  condition  of  chronic  conjunc- 
tival catarrh.  It  may  go  on  to  complete  recovery  or  continue 
unchanged  for  years.  The  complaint  made  by  patients  with  acute 
conjunctivitis  begins  as  a  rule  with  the  statement  that  they  must 
have  sand  in  the  eyes.  This  depends  probably  on  the  roughness 
of  the  mucous  membrane,  which  scratches  the  cornea  or  the  opposed 
mucous  membrane  of  the  globe  at  every  movement  of  the  eyes. 
The  mucous  particles  and  fibers,  too,  play  the  real  part  of  foreign 
bodies.  As  the  disease  progresses  this  feeling  of  "  sand  "  subsides, 
but  the  eyes  still  itch  and  burn  so  that  the  patient  keeps  constantly 
rubbing  them.  Another  complaint  is  that  the  lids  are  heavy  and 
tired.  All  symptoms  are  worse  toward  evening.  Any  strain  on 
the  eyes,  particularly  in  bad  light  or  impure  air,  exaggerates  the 
symptoms.  On  awakening  in  the  morning,  even  if  the  lids  are  not 
stuck  together,  there  is  always  some  difificulty  in  opening  them. 
This  is  almost  always  symptomatic  of  chronic  catarrh.  Apart  from 
,  photophobia  and  other  discomforts  the  patient  is  distressed  by 
optical  disturbances,  which  arise  from  the  deposit  of  mucus  and 
pus  on  the  surface  of  the  cornea,  and  can  for  the  time  being  be 
wiped  away  by  frequent  winking;  these  disturbances  are  hazy 
vision,  polyopia,  appearances  of  rays  of  light  and  colored  rings  and 
flames. 

Catarrhal  conjunctivitis  is  the  commonest  disease  of  the  eye. 
No  wonder -that  special  importance  is  laid  upon  the  question  as  to 
its  cause.  Its  frequency  among  millers,  stonemasons,  and  other 
workers  in  a  dust-laden  atmosphere  shows  that  irritation  by  minute 
foreign  bodies  is  one  of  them.  Another  source  of  catarrh  is  found 
in  the  contagious  diseases,  for  conjunctivitis  is  one  of  the  most  fre- 


CONJUNCTIVITIS    CATARRHALIS    SIMPLEX.  I  8/ 

quent  accompaniments  of  measles,  scarlet  fever,  and  such  eruptive 
disorders.  A  bond  of  union  may  be  suspected  between  such  dif- 
ferent causes,  especially  if  we  consider  further  that  dirty  children 
are  most  prone  to  an  attack  ;  that  this  attack  nearly  always  affects 
both  eyes;  that  a  cold  often, and  a  dacryocystoblennorrhea  always, 
leads  to  a  conjunctivitis  ;  and,  finally,  that  the  disease  is  to  a  cer- 
tain extent  spread  directly  by  its  secretions  and  may  appear  as  an 
epidemic.  This  bond  of  union  is  undoubtedly  infection.  On  every 
conjunctiva  there  are  bacteria, — some  innocent,  some  pathogenetic^ 
and  the  secretion  of  a  diseased  conjunctiva  is  naturally  more 
crowded  with  them.  The  particular  causes  of  the  disease  can 
therefore  be  conveyed  by  a  bit  of  mucus,  a  dirty  hand,  or  dust 
from  the  air,  but  what  these  bacteria  are,  or  what  kind  of  patho- 
genetic germs  are  necessary,  is  at  present  the  subject  of  bacterio- 
logical investigation.  For  the  moment  the  tendency  is  to  assume 
that  the  germs  produce  a  substance,  a  ptomain  or  toxin,  the  small- 
est quantity  of  which  irritates  intensely.  This  view  is  supported 
by  the  fact  that  a  severe  catarrh  may  result  from  the  irritation  of 
some  gas,  such  as  sulfurous  acid  in  the  atmosphere  ;  or  from  the 
irritation  of  some  chemical,  such  as  corrosive  sublimate  in  watery 
solution.  Large-sized  foreign  bodies,  if  remaining  for  a  long  time  in 
the  conjunctival  sac,  may  produce  catarrh.  Any  mechanical  abuse 
of  this  delicate  membrane  seems  sufficient  to  irritate  it. 

Treatment  must  be  directed  first  to  the  suppression  of  demon- 
strable causes — the  removal  of  foreign  bodies,  extraction  of  wild 
hairs,  and  the  cure  of  any  affection  of  the  lacrimal  sac.  The  dis- 
charges and  the  scales  must  be  immediately  removed  by  washing 
with  lukewarm  water  or  a  sublimate  solution  /  .•  jooo.  This  is  sim- 
plified if  the  lids  are  anointed  every  evening  with  vaselin,  pure,  or 
sublimated  o.ooj  :  lo.  To  spare  the  eyes,  to  avoid  fierce  light, 
smoke,  or  dust,  must  be  insisted  on,  though  it  is  often  of  no  avail. 
Direct  medication  aims  to  reduce  and  to  dry  up  secretion  and  to 
encourage  the  swelling  to  go  down.  For  this  purpose  the  most 
commonly  used  applications  are  sulfate  of  zinc  and  nitrate  of  silver 
as  applied  in  the  treatment  of  dry  catarrh.  The  frequency  of  the 
nitrate  of  silver  applications  depends  upon  the  amount  of  dis- 
charge;  if  there  is  very  much,  once  every  twenty-four  hours  is 
none  too  often  ;  if  by  this  means  the  secretion  noticeably  dimin- 
ishes, every  second  day  will  suffice,  and  on  the  intervening  day  a 
zinc  solution,  morning  and  night,  may  be  used.    Immediately  after 


1 88  DISEASES    OF    THE   CONJUNCTIVA. 

applying  the  nitrate  of  silver  any  remaining  fluid  is  to  be  washed 
away  by  a  simple  chlorid  of  sodium  solution ;  if  the  caustic  effect 
of  the  silver  is  very  irritating,  cold  compresses  should  be  used  for 
half  an  hour.  As  a  rule,  these  means  will  be  successful  in  obtaining 
a  rapid  improvement  and  a  cure  within  one  to  two  weeks. 

Many  ophthalmolc^sts  apply  cold  compresses  at  the  commencement  of  a  conjunc- 
tivitis. I  cannot  recommend  it ;  especially  as  patients  often  resort  to  this  domestic  remedy 
themselves,  and  though  the  symptoms  are  for  the  moment  less  distressing,  the  condition 
as  a  whole  has  been  made  worse.  If  nitrate  of  silver  and  zinc  are  not  effective,  we  must 
try  other  astringents,  as  tannin  l.o  to  30.0  or  plumbum  aceticum  0.2  to  30.0.  It  is  always 
advisable  to  examine  the  eye  again  to  see  whether  some  continued  cause  of  irritation  has 
not  been  overlooked,  such  as  a  foreign  body,  misplaced  hairs,  a  tear  sac  inflammation, 
improper  use  of  the  eyes,  or  perhaps  a  small  corneal  ulcer. 

Any  sequelae  of  catarrh,  as  inflammation  of  the  lid  edge  or  eczema,  should  be 
treated  according  to  the  rules  already  given  (//.  144  et  T4g).  Small  fissures  in  the  exter- 
nal canthus  give  particular  trouble.  Saemisch's  view  is  that  these  heal  with  such  difficulty 
because  the  lashes  of  the  upper  lid  are  always  injuring  the  scarcely  restored  skin  in  that 
place.  Cutting  off  the  neighboring  hairs  is  very  effective.  My  opinion  is  that  these  little 
fissures  do  not  owe  their  origin  to  the  lashes  but  to  the  hand  of  the  phj-sician,  or  to  the 
refusal  of  the  patient  to  open  his  lids. 

{d)  Blennorrhea  {Conjunctivitis  blennorrhoica,  sive  purulentd). — 
The  essential  characteristics  of  blennorrhea  are  redness  and  swell- 
ing of  the  entire  conjunctiva,  excessive  formation  of  pus,  and  in- 
volvement of  lids,  skin,  and  even  lymph  glands  behind  the  ear. 

The  secretion  is  at  first  thin,  but  slightly  cloudy,  and  is  of  a 
citron-yellow  color,  due  to  blood  pigment.  In  proportion  as  the 
secretion  becomes  richer  in  cells  is  it  thicker  and  cloudier  and  of  a 
more  pronounced  yellow  ;  it  wells  up  over  the  lid  edges  and  lies  on 
the  lids,  partly  as  a  fluid,  partly  as  dry  crusts.  The  inner  surface 
of  the  lids  is  often  covered  with  a  thin  and  transparent  layer  of 
coagulated  secretion  ;  these  pseudo-membranes  are  very  apt  to  be 
formed  on  exposure  of  the  mucous  membrane  to  the  air.  If  the 
disease  has  passed  its  height,  the  secretion  is  less  in  amount  and 
becomes  more  mucus-like  in  character.  For  this  reason  the  stages 
have  been  called  those  of  dacryorrhea,  pyorrhea,  and  blennorrhea. 

At  its  commencement  the  disease  looks  like  a  simple  conjuncti- 
vitis, but  in  a  few  days  the  hyperemia  and  swelling  increase  enor- 
mously ;  the  conjunctiva  is  red,  smooth,  and  shiny,  not  only  on  the 
lid  and  at  the  fornix  but  also  on  the  eyeball.  The  swelling  of  the 
conjunctiva  on  the  eyeball  reaches  such  a  degree  that  a  dark  red 
mass  crowds  between  the  lids,  chemosis  cotijunctiz'ce.  Indeed,  the 
inflammation  involves  the  lid  edge  and  the  skin  ;  the  upper  lid,  hot. 


BLENNORRHEA. 


189 


red,  edematous,  with  its  wrinkles  obliterated,  hangs  down  above 
the  lower,  too  heavy  for  the  levator  to  raise  it,  too  thick  to  pass  into 
its  place  beneath  the  roof  of  the  orbit ;  the  ptosis  is  now  complete. 
When  the  storm  has  raged  its  worst,  the  swelling  of  the  lids  and 
conj  unctiva  decreases,  and  at  the  fornix  and  the  adjacent  conjunctiva 
on  the  lid  there  can  be  seen  those  uneven  places  already  mentioned, 
the  so-called  papillae.  Fig.  y2  gives  an  idea  of  the  anatomical 
changes  in  the  conjunctiva  of  the  lid:  A  large  papilla  is  seen;  at 
the  base  of  it  are  cross  sections  of  blood-vessels  {a  a),  and  just  be- 
neath the  epithelium  is  a  network  of  finer  ones  {i>  £>);  the  whole 
papilla  is  strewn  with  round  lymph  or  pus  cells,  particularly  abun- 
dant near  the  vessels.     The  upper  layer  of  epithelium  consists  of 


^"IG.  72. — Hyperirophied  Papili..«  of  a  Blennorrheic  Conjunctiva.     (A/ier  StEmisch  ) 

cylindrical  cells  that  appear  remarkably  long  in  the  pits  between 
the  papillae. 

The  disease,  if  left  entirely  to  itself,  can  run  its  course  to  com- 
plete recovery  in  two  or  three  weeks.  The  skin  and  the  conjunc- 
tiva of  the  globe  are  the  first  to  recover  their  normal  character ; 
the  conjunctiva  of  the  lids  the  last.  As  a  rule,  however,  recovery 
halts  half  way;  the  swollen  papillae  do  not  shrink  together,  the 
production  of  pus  and  mucous  does  not  completely  cease,  and  acute 
blennorrhea  passes  into  the  chronic  stage.  This  may  last  for 
months  or  years,  and  at  any  moment  the  inflammation  may  blaze 
up  into  an  acute  form  again.  The  change  from  acute  to  chronic 
blennorrhea  is  not  always  the  worst  that  may  threaten  the  patient. 


IQO  DISEASES    OF    THE   CX)NJUNCT1VA. 

This  disease,  much  more  thaa  at  simple  conjunctivitis,  has  the  ten- 
dency to  cause  corneal  ulceration,  and  may  thereby  destroy  the 
eye  (panophthalmitis  ending  in  phthisis  bulbi),  or  may  at  least  do 
great  damage  ^^leucoma  or  corneal  scars).  The  reason  for  this 
danger  to  the  cornea  is  easy  to  sec.  The  intense  swelling  of  the 
coojuncti\'a  near  the  cornea  squeezes  the  blood-vessels  that  carrj- 
aourishment  to  it :  the  swc^Ien  and  stretched  upper  lid  irritates  the 
cornea  mechanically,  the  ceaseless  flood  of  pus  macerates  the  pro- 
tective epithelium,  and  finally,  if  the  smallest  crevice  appears  in  the 
epithelium,  the  nature  of  the  pus  is  such  that  a  direful  infection 
results  through  the  wound, 

I  kcve  jasi  beca  tiKnii^wg  t«x>  esses  in  wkaA  p— OfilWli»1rQiti$  developed  after  years 
kad  passed.  la  one  case  Ae  e3re  bad  beea  cofltXihy  qaaescent  after  a  blenoonbea  and 
aafyiii  itko  io  the  cxxcea,  in  the  secood  li>e  inl^ii— arina  bad  beea  bf^ted  iq>  at  into-rals. 


The  sjTnptoms  of  the  patient  are  about  the  same  as  those  of  a 
simple  conjunctivitis.     It  should  be  mentioned  that  the  severe  pain 
at  the  commencement  generally  diminishes  as 
soon  as  *'  pyorrhea  "  begins. 

The  cause  of  the  disease  is  better  knouTi  than 

^^^  ^4S[^      is  that  of  any  other  conjunctivitis.    We  are  sure 

^5^  ^~-vjr        ^^^^  ^  well-defined  germ,  the  gonococcus  of 

Fis,  73  — Gojwcocct  ut      Xeiser  (Z^^"^-  ~?),  is  the  cause  of  all  malignant 

jAcw  rfuH  t,  SMMomJi        cases  and  is  present  m  many  of  a  milder  t^-pe. 

The  source  of  the  infection  can  usually  be 

detected  without  diflRcult\\     Many  children  are  infected  during  or 

after  birth  by  the  coccus-bearjng  mucus  of  the  maternal  passages, 

BUnnorrkem  memtmitmm.     In  other  cases  patients  infect  themselves 

by  cardessly  wiping  the  pus  of  a  dap  into  their  eyes  with  their 

hands,  the  right  eye  bang  most  often  affected — Cat^umctivitis  gvm^r- 

rktica.     This  kind  of  affection  is  found  only  in  men  and  female 

children. 

Conjuncti\4tis  gonorrhoica  has  two  characteristics  to  distinguish 
it  firom  blennorrhea ;  first,  the  swelling  of  the  upper  lid  to  a  board- 
like hardness,  and  second,  swelling  of  the  IxTiiph  glands  in  front  of 
the  ear.  Conjunctivitis  gonorrhoica  is  rare  in  proportion  to  the 
frequency  of  dap.  This  is  due  less  to  caution  and  deanliness  on 
the  part  of  the  clap  sufferers  than  to  the  circumstance  that  gon- 
orrheal pus  loses  its  infectiousness  by  being  so  thinned  with  fluids 
and  by  being  long  in  a  dr\-  state. 

Ever>-  blennorrhea  is  not  caused   by  the  gonococcus.     There 


BLElfXORRHEA.  I9I 

are  other  germs,  presumably,  that  can  produce  similar  changes  in 
the  conjunctiva.  At  any  rate,  many  blennorrheas,  especially  those 
of  the  new-born,  have  been  observed  without  the  gonococcus,  but 
these  cases  are  essentially  distinguished  from  those  caused  by  the 
gonococcus  by  a  later  onset,  at  the  fifth  to  the  twelfth  day  after 
birth  (the  malignant  cases  begin  on  the  second  or  third  day),  by 
a  milder  course,  and  particularly  by  a  shorter  period  of  life  and  by 
the  immunity  of  the  cornea. 

Again,  mechanical  and  chemical  accidents  to  the  conjunctiva  can 
start  up  a  condition  of  blennorrhea. 

Ssemisch  mentions  that  an  "  artificial  eye  "  may  at  timtts  caase  cimiwln  ihle  nitadiM 
to  the  conjanctiva,  and  in  case  it  is  not  taken  out  at  ooce,  it  may  even  prodace  a  bieat- 
norrhea.  I  myself  once  had  this  experience  :  I  was  called  to  see  a  peasaat,  wbooi  I 
found  with  the  perfect  picture  of  a  fresh  blenoorrfaea,  and  wild  from  pain.  .After  ques- 
tioning him  1  found  that  he  had  a  mild  conjunctival  catarrh,  and  M  the  advice  of  a  friend 
had  bathed  it  with  a  mixture  of  salt  and  French  brandy  !  Undotditedly  tlus  friend  had 
observed  that  physicians  "  stimulated  "  inflamed  eyes,  and  he  had  imitated  tbe  proces* 
according  to  his  light. 

Treatment  should  be,  above  all,  to  avoid  the  disease.  Bjy  proper 
precautions  every  case  of  blennorrJiea  neonatorum  can  be  prevented. 
To  Crede  belongs  the  immortal  honor  of  having  found  an  effective 
agent  against  it.  His  method  consisted  in  carefully  cleaning  the 
eyes  in  the  bath  and  then  in  dropping  a  few  drops  of  a  two  per  cent. 
solution  of  nitrate  of  silver  "  exactly  on  the  cornea"  of  any  child 
born  of  a  mother  with  a  gonorrhea.  The  drops  spread  over  the 
conjunctiva,  scale  off  the  superficial  epithelium,  and  thereby  destroy 
all  gonococci  that  have  not  so  far  penetrated  beneath  the  surface. 

Since  this  disinfection  is  always  painful  (perhaps  to  a  tender  mother  more  than  to  the 
child),  and  causes  a  conjunctival  hyperemia,  it  has  been  proposed  to  replace  Crede's 
method  by  washing  with  sterilized  water,  chlorin  water,  solution  of  potassinin  perman- 
ganate, or  even  with  corrosive  sublimate  I  :  5000.  Ahlfeld  would  not  disinfect  the 
conjunctiva  at  all,  bat  would  replace  that  by  radical  disinfection  of  the  lying-in  woman. 
This  may  be  possible  in  a  well-conducted  ob^etrical  hospital,  bat  in  ordinary  practice  it 
is  out  of  the  question.  Preference  must  be  given  without  cooditioD  to  the  simple  and 
sure  method  of  Crede,  although  the  drops  need  not  fall  '*  exactly  on  the  cornea,"  so  kmg 
as  they  reach  the  conjunctival  sac  in  some  way. 

Prophylactic  measures  nfust  be  taken  for  the  other  eye,  in  case 
the  patient  comes  to  the  physician  with  only  one  eye  attacked.  In 
adults  (conjunctivitis  gonorrhoica)  it  is  best  to  wash  and  disinfect 
the  sound  eye  externally  and  then  to  wash  out  the  conjunctival  sac 
with  sublimate  solution  /  .-  S^^^^  ^^^  immediately  afterward  to 
isolate  it  with  a  bandacre  of  sublimate  cotton.     In  infants  such  a 


192  DISEASES   OF   THE    CONJUNCTIVA. 

bandage  is  impracticable;  we  must  be  content  to  linstruct  the 
mother  or  nurse,  and  to  have  the  child  lie  so  that  the  pus  welling 
from  the  diseased  eye  may  not  overflow  into  the  healthy  one. 

Fraenkel  has  had  good  results  with  no  bad  luck  in  applying  daily  a  drop  of  two  per 
cent,  nitrate  of  silver  to  the  healthy  eye. 

If  the  disease  is  once  started  the  best  method  to  pursue  is  the 
following :  the  attendants  must  get  a  large  bottle  of  sublimate 
solution  /  .•  5000,  a  package  of  absorbent  cotton,  and  be  directed 
to  open  the  lids  every  hour  of  the  day  and  night,  to  wipe  off  the 
pus  with  moist  sublimate  cotton,  then  to  dry  the  eye  and  to 
put  in  the  fissure  and  on  the  lids  some  vaselin,  either  sublimated 
(o.ooj  .'  10.0)  or  borated  (/  .•  10.6).  This  prevents,  to  a  certain 
extent  at  least,  the  pernicious  action  of  the  pus  on  the  epithelium 
of  the  cornea  and  on  the  tender  epidermis  of  the  lids.  The  physi- 
cian must  paint  the  conjunctiva  of  the  lids  and  fornix  once  a  day 
with  two  per  cent,  solution  of  silver.  In  the  second  stage,  if  the 
conjunctiva  is  thick  and  velvety,  stronger  solutions,  say  five  per 
cent,  of  nitrate  of  silver,  are  indicated.  In  the  third  stage  the  two 
per  cent,  solution  can  be  returned  to,  but  the  application  need  be 
made  only  every  second  day,  in  the  interval  zinc  solution  being 
used. 

Results  from  such  treatment  are  good.  As  a  rule,  decided  im- 
provement is  already  noticeable  after  the  first  or  second  application, 
but  several  weeks  are  necessary  to  effect  a  complete  cure. 

The  cornea  must  be  watched  continuously,  and  any  attack  on  it 
should  be  treated  according  to  the  principles  given  on  p.  2j^. 
Corneal  involvement  is  no  contra-indication  to  the  nitrate  of  silver 
treatment.  In  blennorrhea  of  the  new-born  the  disease,  as  a  rule, 
runs  its  course  without  attacking  the  cornea ;  in  conjunctivitis 
gonorrhoica  of  adults,  on  the  other  hand,  the  cornea  is  very  often 
destroyed,  or  at  least  endangered. 

Many  surgeons  apply  constant  ice  poultices  during  the  first  stage  of  the  disease 
(dacryorrhea).  I  consider  this  superfluous,  if  not  harmful.  It  must  also  be  mentioned 
that  formerly  it  was  quite  general  to  resort  to  ca^iterization  with  the  nitrate  of  silver 
pencil,  or  with  the  lapis  mitigatus  (^Argent,  nit.  i.o.  Kali  2).  I  could  never  induce 
myself  to  use  it,  nor  can  I  ever  see  wherein  lies  the  advantage  of  the  pencil  over  fluid 
applications.  Local  blood-letting  has  been  used  ;  that  is,  scarifications  by  shallow,  longi- 
tudinal incisions  in  the  conjunctiva  of  the  fornix.  Bloodletting  is  indicated  where  a 
p)eculiar  dark-red  color  of  the  mucous  membrane  suggests  a  slow  and  impeded  blood 
current.  If  the  lids  are  strongly  everted,  a  profuse  hemorrhage  may  take  place  sponta- 
neously.     It  may  sometimes    be  necessary  to   split  the  external  canthus  down  to  the 


CONJUNCTIVITIS    CROUPOSA.  1 93 

orbicularis  muscle,  and  to  keep  the  wound  open  for  some  time,  in  order  to  relax  the 
upper  lid  and  thus  to  lessen  the  serious  pressure  of  this  lid  on  the  cornea.  At  the  same 
time  the  hemorrhage  caused  by  this  procedure  acts  favorably  in  reducing  the  congestion 
of  the  conjunctiva. 

(e)  Conjunctivitis  crouposa  (C  membranacea,  Croupous  Inflammation). — The  pic- 
ture of  this  disease  is  in  many  respects  even  to-day  a  confusing  one.  One  author  declares 
that  it  is  very  infrequent,  another  says  that  it  is  common ;  one  calls  it  mild,  another 
severe  ;  one  affinns  it  to  be  infectious,  another  not.  At  any  rate,  we  may  conclude  from 
this  that  the  disease  appears  in  many  forms  and  is  of  variable  frequency  in  different 
neighborhoods.  It  is  characterized  as  a  more  or  less  pronounced  inflammation  of  the 
conjunctiva  of  the  lid  and  fornix,  with  the  formation  of  a  yellowish  membrane  which  can 
be  rather  easily  lifted  from  the  mucous  surface.  Such  a  description  may  under  certain 
circumstances  be  given  to  blennorrhea  also,  and  it  may  occasionally  happen  that  the  same 
case  will  be  called  by  one  surgeon  conjunctivitis  crouposa,  and  by  another  blennorrhea 
pseudo-membranosa.  Nevertheless,  it  is  quite  possible,  and  therefore  of  practical  impor- 
tance, to  distinguish  these  two  forms  of  disease,  because  treatment  of  the  croupous  inflam- 
mation of  the  conjunctiva  is  quite  different  from  that  of  the  suppurative  form. 

At  the  beginning  the  lids  are  swollen  and  red,  but  soft  and  only  moderately  sensitive. 
The  upper  lid,  heavy  and  immovable,  hangs  over  the  under  one.  Between  the  lids  there 
wells  up  in  more  or  less  profusion  a  quantity  of  watery  secretion  mixed  with  a  little 
mucus.  If  the  lids  are  everted,  one  finds  in  severe  cases  the  whole  conjunctiva  of  the 
lids  and  fornix  covered  with  a  yellowish,  untransparent  membrane ;  in  the  worst  cases 
the  conjunctiva  of  the  globe  is  also  affected,  being  congested  and  covered  with  the  same 
membrane  ;  but  in  the  mildest  cases  the  croupous  membrane  consists  of  only  small  white 
islands  lying  near  the  edge  of  the  lid  and  leaving  the  fornix  and  the  entire  conjunctiva  bulbi 
free.  If  the  covering  is  detached  there  is  a  slight  hemorrhage  from  the  mucous  mem- 
brane, leaving  it  rough  and  pimply,  dark-red,  and  rather  swollen.  This  covering  is  formed 
anew  on  the  next  day.  After  a  period  of  from  two  to  six  days  the  membranes  are  cast 
off  of  themselves  and  are  not  renewed,  while  at  the  same  time  the  secretion  becomes 
ordinary  pus,  the  conjunctivitis  crouposa  having  entered  upon  the  blennorrhea!  stage,  from 
which  it  may  pass  to  a  complete  cure.  In  many  cases  the  course  is  different.  The 
membrane,  whether  torn  or  cast  off,  is  repeatedly  formed  anew.  Manz  reports  a  case  in 
which  membrane  was  still  forming  after  half  a  year.  In  about  40  per  cent,  of  cases  there 
is  a  mild  or  severe  corneal  infection.  The  majority  of  cases,  however,  heal  quickly  and 
completely. 

Pathological  anatomy  of  these  croupous  membranes  shows  them  to  consist  of  fibrin 
fibers  filled  with  pus  and  epithelium  cells.  Distinct  layers  are  demonstrable  in  them  ; 
their  structures  being,  therefore,  the  same  as  that  of  the  membrane  in  laryngeal  croup. 
The  thickness  of  the  membrane  may  vary  from  o.  t  to  /.j:  mm.  (Knapp). 

In  considering  the  origin  of  the  disease  we  must  notice  the  circumstance  that  it  usu- 
ally appears  on  children  with  eczematous  skin  eruptions  on  the  head,  and  with  other 
signs  of  scrofula.  If  one  remembers,  moreover,  that  according  to  Lotz  half  the  children 
are  attacked  in  only  one  eye,  and  that  the  eye  which  remains  unattacked,  in  spite  of  neg- 
lected precautions,  belongs  to  that  side  of  the  head  \yhich  is  also  free  from  eruption,  the 
conclusion  cannot  be  avoided  that  the  skin  eczema  is  the  cause  of  the  disease.  The  why 
of  the  case  may  find  some  solution  in  the  great  epidemic  that  raged  during  1882  to  1884 
in  many  centers  of  ophthalmic  activity  :  At  v.  Wecker's  suggestion  many  surgeons  tried 
to  cure  a  corneal  pannus  by  painting  the  conjuncti%'a  with  a  watery  extract  of  jequirity 
seeds.  This  always  produced  a  regular  croupous  conjunctivitis  and  often  the  desired 
subsidence  of  the  pannus.  But  since  the  effect  of  jequirity  is  to  a  certain  extent  purely 
13 


194  DISEASES    OF    THE    CONJUNCTIVA. 

chemical,  the  idea  suggested  itself  that  the  secretion  from  an  eczematous  skin  surface  was 
the  cause  of  an  analogous  effect  on  a  susceptible  conjunctiva.  This  by  no  means  ex- 
cludes the  possibility  of  germs  producing  the  same  effect.  Many  cases  have  been  de- 
scribed in  which  conjunctival  croup  appeared  simultaneously  with  laryngeal  or  tracheal 
croup,  presumably  from  the  same  cause. 

Treatment,  tested  in  Schiess'  clinic,  and  recommended  by  Lotz,  begins  with  an  attack 
on  the  skin  eczema,  the  principal  dependence  being  placed  on  applications  of  white 
precipitate  ointment  i^Hydrarg.  pracip.  alb.  i.o,  Vaselin  20.6)  to  the  skin.  The  eyes 
are  washed  several  times  daily  with  a  carbolic  or  sublimate  or  boric  acid  solution,  and  the 
membrane  carefully  removed  if  possible.  The  chief  local  treatment  consists  of  nearly 
continuous  compresses  of  lukewarm  lead  water  to  the  eyes.  ^  Applications  of  nitrate  of 
silver  are  unconditionally  forbidden  and  may  not  be  applied  until  the  croupous  condition 
has  passed.  With  this  treatment  a  cure  will  be  obtained  in  from  ten  to  thirty  days.  Any 
corneal  disease  showing  itself  is  to  be  treated  according  to  the  principle  given  on  p.  226. 
Special  protective  measures  need  not  be  taken  for  an  unaffected  eye,  although,  of  course, 
an  infection  with  secretion  must  be  carefully  avoided,  for  every  conjunctival  secretion 
contains  germs  of  various  kinds.  Even  if  in  one  case  they  were  only  harmless  parasites, 
it  must  not  be  taken  for  granted  that  in  another  case  they  would  not  produce  disease. 

(/")  Conjunctivitis  diphtheritica. — The  production  of  coagu- 
lating secretion  on  the  surface  of  the  conjunctiva  is  characteristic 
of  croup,  but  in  diphtheria  there  is  an  inflammatory  condition  in 
which  a  firm  exudate  lies  within  the  tissue  of  the  mucous  mem- 
brane itself.  The  croupous  membrane  may  therefore,  in  the 
severest  cases,  carry  the  epithelium  with  it,  but  when  the  diphther- 
itic membrane  is  cast  off  the  mucous  membrane  itself  is  destroyed 
also.  A  croupous  mucous  membrane  heals  with  restoration  of  its 
former  structure;  a  diphtheritic  mucous  membrane  always  heals 
with  the  formation  of  scar  tissue. 

Conjunctivitis  diphtheritica  always  produces  a  grave  disturbance 
of  the  general  system,  with  fever  and  its  consequences.  The  local 
picture  is  that  of  blennorrhea  at  its  height.  To  avoid  repetition  I 
shall  give  here  only  the  differential  diagnosis  :  In  diphtheria  the 
upper  lid  is  bluish-red  and  so  swollen  that  it  feels  hard  and  unyield- 
ing. To  the  touch  it  is  hot  and  exquisitively  sensitive,  so  exqui- 
sitely sensitive  that  even  the  hands  of  a  v.  Graefe  or  a  Horner  were 
unable  to  evert  the  lids  so  as  to  see  the  inner  surface  without  mak- 
ing the  patient  shriek  with  the  frightful  pain  ;  chloroform  had  to  be 
used  in  order  to  make  a  proper  examination.  In  the  worst  cases  a 
complete  eversion  of  the  upper  lid  is  impossible.  If  the  upper  lid 
is  raised  an  abundant,  thin,  discolored  fluid,  full  of  yellowish  flakes, 


^  Warm  compresses  of  three  per  cent,  boric  acid  solution  have  been  equally  efficacious 
in  my  hands,  and  are  free  from  the  danger  of  lead  deposits. 


CONJUNCTIVITIS    DIPHTHERITICA,  I95 

escapes.  The  conjunctiva  of  the  lid  appears  grayish-white,  smooth, 
and  porklike.  Blood-vessels  are  absent  or  only  partly  visible  ;  the 
conjunctiva  of  the  globe  is  chemotic  and  spotted  with  small  hemor- 
rhages, in  the  worst  cases  looking  like  a  piece  of  raw  ham.  If  the 
conjunctiva  is  cut  no  blood  escapes,  since  the  vessels  are  strangled. 
This  condition  needs  two  to  five  days  for  its  complete  development, 
and  then  remains  for  some  time,  even  as  long  as  eight  days,  un- 
changed. Thesecondstageof  the  disease  now  begins.  The  conjunc- 
tiva becomes  spongy,  relaxed,  and  full  of  blood  ;  the  exudate  poured 
into  the  mucous  membrane  is  partly  absorbed  and  partly  thrown 
off  with  the  necrotic  tissue.  The  secretion  becomes  purulent,  the 
eye  looks  "  blennorrheic,"  but  the  condition  is  quite  different.  In 
blennorrhea  the  red  papillae  are  part  of  the  swollen  mucous  mem- 
brane, while  in  diphtheria  they  are  wound  granulations.  Moreover, 
the  sequelae  are  quite  different ;  in  the  one  case  restoration  of  normal 
tissue,  in  diphtheria  formation  of  a  cicatrix  tissue,  resulting  in  a 
condition  called  xerosis parencJiyuiatosa  [p.  202).  This  atrophy  can 
lead  to  symblepharon  (/.  21'j)  and  to  malpositions  of  the  lids,  and 
may  thereby  endanger  the  visual  power  of  the  eye.  At  the  height 
of  the  disease  one  would  scarcely  think  of  these  curae  posteriores, 
since  the  integrity  of  the  eye  is  threatened  by  the  infinitely  greater 
danger  of  infection  of  the  cornea.  Of  the  ravages  of  the  disease  we 
may  form  some  idea  from  the  fact  that  of  ^o  cases  in  children 
treated  by  A.  v.  Graefe  from  the  beginning,  nine  eyes  were  totally 
destroyed  and  three  seriously  injured  ;  in  adults  it  was  even  worse  : 
of  eight  eyes,  three  were  destroyed,  two  escaped  with  severe,  and 
the  remaining  three  with  mild  impairment  of  the  cornea. 

The  disease  of  the  cornea  begins  as  a  rule  with  a  yellowish  in- 
filtration of  the  center.  As  the  epithelium  is  cast  off  the  infiltrate 
changes  to  an  ulcer  that  increases  the  more  rapidly  in  breadth  and 
depth  the  earlier  the  cornea  was  attacked. 

Diphtheria  results  from  infection.  There  is  no  doubt  that  infec- 
tion with  the  gonococcus  of  Neisser  and  with  the  diphtheria 
bacillus  of  Klebs-Loefifler  can  produce  a  conjunctival  diphtheria. 
Whether  the  same  is  true  of  other  germs  is  not  known.  It  is 
worthy  of  mention,  however,  that  badly  treated  wounds,  such  as  the 
pits  of  blepharitis  ulcerosa,  occasionally  show  a  diphtheritic  cover- 
ing that  spreads  in  isolated  patches  over  the  conjunctiva;  but  these 
foci  of  diphtheria  are  a  relatively  benign  disease — a  fact  that  may 
suggest  an   origin   from   some  other  germ.      A   purely  chemical 


196  DISEASES    OF   THE   CONJUNCTIVA. 

action  may  produce  an  anatomical  picture  of  diphtheria  ;  we  see  this 
in  the  injuries  resulting  from  unslacked  lime,  from  acids,  alkalies, 
jequirity,  and  burns  with  molten  metal. 

Treatment  must  be  directed  largely  to  the  protection  of  the 
healthy  eye  (/.  igi),  if  such  there  be,  both  on  account  of  the  infec- 
tiousness and  of  the  malignity  of  the  disease.  If  the  disease  is 
once  started,  treatment  seems  to  be  futile. 

Ice  compresses,  once  so  warmly  praised  by  v.  Graefe  and  others, 
seem  of  late  years  to  have  met  with  a  cool  reception,  and  by  Ber- 
lin, Burkhardt,  and  others  have  been  altogether  rejected,  because 
the  conjunctiva  is  already  anemic  and  is  endangered  in  proportion 
to  this  impoverishment  of  protective  blood  supply.  Perhaps  mod- 
ern ideas  are  better  conformed  with  if  the  active  attacks  with  ice, 
blood-lettings,  and  such  are  omitted,  and  if  reliance  is  placed  only 
on  frequent  cleansing  of  the  eye  with  a  mild  antiseptic  and  the  use 
of  lukewarm  boric  acid  compresses.  The  incision  through  the 
outer  canthus,  canthoplasty,  cannot  always  be  avoided  ;  it  reduces 
the  pressure  of  the  upper  lid  on  the  already  poorly  nourished 
cornea.  If  the  membrane  begins  to  be  cast  off  there  is  no  doubt 
of  the  efficacy  of  hot  compresses  and  mild  astringents.  As 
Horner  says,  caustics  are  to  be  omitted,  since  they  would  only  en- 
courage cicatricial  contraction.  At  the  most,  when  pus  is  freely 
produced  or  when  the  isolated  granulations  are  unusually  profuse, 
silver  nitrate  is  indicated. 

Walfring  advises  massage  of  the  inner  surface  of  the  lid  with  yellow  precipitate 
ointment.  Is  this  possible,  considering  the  frightful  pain  of  severe  diphtheria  ?  Fieuzal 
has  seen  good  effect  from  lemon  juice,  Mayweg  from  iodoform  powder,  Tweedy  from 
quinin  solution,  Vossius  from  salicylic  glycerin  solution,  and  Hotz  from  carbolic-iodin- 
alcohol  solution.  The  more  hopeless  the  results  of  treatment,  the  greater  the  number  of 
remedies  exploited. 

2.  INFLAMMATIONS  WITH  FORMATION  OF  FOLLICLES. 
(a)  Conjunctivitis  follicularis  {Follicular  Catarrh). — It  is  still 
a  disputed  point  whether  lymph  follicles  {p.  182)  are  normally  pre- 
sent in  a  healthy  conjunctiva,  but  this  much  is  certain,  that  in  a 
healthy  conjunctiva  no  lymph  follicles  can  be  seen  with  the  naked 
eye.  In  the  disease  under  discussion,  on  the  contrary,  the  naked 
eye  can  see  them  on  the  mucous  membrane  as  pale  red,  more  or 
less  translucent,  roundish  protuberances.  They  lie  in  the  fornix  of 
the  lower  lid  {Fig.  J4),  row  on  row ;  the  upper  lid  is  free,  although 
at  the  inner  and  outer  angles  small  clusters  may  be  found. 


CONJUNCTIVITIS    FOLLICULARIS.  I97 

Follicular  catarrh  may  be  acute  or  chronic.  The  acute  form 
begins  as  a  simple  conjunctivitis,  that  is,  with  a  secretion  at  first 
of  a  watery  but  finally  of  a  muco-purulent  character.  During  the 
first  week  of  the  disease  suspicion  may  be  soonest  awakened  by 
the  circumstance  that  the  fornix  in  particular  seems  reddened  and 
swollen  :  the  follicles  are  already  there,  though  not  yet  visible. 
They  cannot  be  seen  till  the  congestion  of  the  conjunctiva  recedes, 
when  they  glisten  faintly  through  the  overlying  membrane.  If  the 
hyperemia  and  swelling  of  the  conjunctiva  recede  still  more,  the 
follicles  rise  above  the  surface  and  complete  the  pathological 
picture.  A  noteworthy  sign  deserves  mention,  namely,  that  the 
lower  lid  is  somewhat  crowded  away  from  the  eyeball  by  these 
follicles,  in  such  a  way  that  between  the  lid  and  the  ball  a  pit  is 
formed,  which  is  filled  up  with  tears.  Michel  declares  that  besides 
this,  in  the  majority  of  cases  the  lymph 
glands  in  front  of  the  ear  are  swollen. 

Follicular  catarrh  may  develop  with- 
out acute  symptoms,  warranting  us  in 
speaking  of  a  chronic  form  of  the  dis- 
ease. Its  duration  is  very  variable,  last- 
ing sometimes  four  to  eight  weeks, 
sometimes  months  and  years.  Healing 
takes  place  by  absorption  of  the  con- 
tents of  the  follicles  and  disappearance      fig.  74  — Nodules  on  the  Lower 

/.   ^ ,  ,     .  Fornix  in  Follicular  Catarrh. 

Ot    the  nodules.  (A/ter  SUhel.) 

The  obstinacy  of  follicular  catarrh 
suggests  the  conclusion  that  it  is  a  much  more  severe  disease  than 
simple  conjunctivitis.  A  further  evidence  of  this  lies  in  the  fact  that 
follicular  catarrh  is  more  prone  to  relapses,  and  to  attack  the  cornea 
during  its  course.  This  latter  shows  itself  at  first  with  "  pericorneal 
injection."  the  precursor  of  shallow  ulcers  at  the  corneal  margin. 
Since  these  ulcers  are  in  the  immediate  neighborhood  of  blood- 
vessels {Fig.  80,  p.  221),  every  circumstance  favors  a  speedy  vascu- 
larization and  recovery.  A  farther  difference  from  simple  catarrh 
lies  in  the  facts  that  the  follicular  form  is  more  infectious  than  the 
simple,  both  eyes  being  nearly  always  attacked,  and  that  epidemics 
are  not  infrequent;  schools,  barracks,  asylums,  prisons,  in  short,  all 
buildings  where  persons  are  penned  together,  provide  a  romping 
ground  for  such  epidemics.  Suspicion  has  been  directed  against 
some  germ  as  the  cause  of  the  disease,  and  investigators  have 


198  DISEASES   OF  THE  CX)XJUXCT1VA. 

attempted  to  demonstrate  a  micrococcus  which  by  many  is  con- 
sidered identical  with  the  trachomacoccus  (/.  20j). 

FoUknlar  catarrli  is  said  to  be  produced  bf  chemical  acdoo,  esperially  hr  atropin,  as 
wdl  as  by  infection.  It  b  a  fact  that  the  continaed  ose  of  atiopin  wiD  li^  ap  a  UOacm- 
]ar  conjoDctiTitis,  but  another  fact  b  that  atropio  loltions  a*  kMtmulf  ased  withoal  the 
addition  of  some  sublimate,  become  fall  of  germs  after  awhile,  so  that  tageAgr  widi  the 
atiopin  all  manner  of  germs  vere  dropped  into  the  ooojuictiral  sac.  Maaj  ioimigjtws. 
like  Raehlmann  and  Michel,  discard  the  term  ''atropin  coajoDctititis,''  vUle  others 
insist  that  sterile  solutions  and  eren  dry  atropin  are  capable  of  prodncing  follicalar  catarrh. 
Xerertheless,  "atropin  follicles  "  hare  grown  less  since  dry  atropin  was  placed  on  the 
coDJanctivitis.     I  cannot  say  that  I  hare  erer  seen  an  nndoabted  case  of  it. 

As  compared  with  that  of  simple  catarrh,  the  prognosis  is  un- 
favorable on  account  of  its  prolonged  course  and  tendency  to  relapse, 
but  as  compared  with  that  of  trachoma,  about  to  be  described,  it 
is  favorable,  for  the  follicles  disappear,  no  scar  remains,  the  tarsus 
is  unaffected,  and  the  cornea  is  not  seriously  attacked— conditions 
that  all  prevail,  unfortunately,  in  trachoma. 

Treatment  should  begin  with  measures  to  protect  the  healthy 
eyes  of  the  patient's  associates.  If  there  is  an  epidemic  in  the 
house,  the  sick  should  be  isolated,  taken  care  of  in  well-ventilated 
rooms,  and  encouraged  to  pass  as  much  time  as  possible  out- 
doors where  the  air  is  free  from  dust.  Without  this  "fresh- 
air  cure "  too  much  cannot  be  expected  of  local  treatment.  As 
far  as  this  is  concerned,  it  is  a  rule  that  the  follicles  themselves  do 
not  need  direct  treatment.  The  hj'peremia  and  swelling  at  the 
fornix  can  be  attacked  with  shallow  incisions,  the  pathological 
secretions  by  the  remedies  mentioned  under  the  treatment  of  simple 
catarrh.  The  secretion  itself  must  be  washed  away  with  sublimate 
solution  and  made  harmless.  If  in  spite  of  this  treatment  the  ab- 
sorption of  the  follicles  is  delayed,  the  fornix  may  be  touched 
every  second  or  third  day  with  "  blue  stone  "  (a  pencil  of  sulfote 
of  copper  polished  smooth  with  a  wet  cloth).  The  smarting  that 
follows  and  lasts  for  about  half  an  hour  can  be  soothed  and  short- 
ened by  cold  compresses.  The  subsequent  short  but  pronounced 
hyp)eremia  that  follows  encourages  the  absorption  of  the  contents 
of  the  follicles.  If  this  does  not  achieve  its  purpose,  the  follicles 
may  be  squeezed  out  with  ciliar)'  forceps  {fig^-  JJ?,  /.  ijo)  after 
cocainizing  the  conjunctiva,  of  course. 

If  corneal  ulcers  appear,  atropin  and  a  bandage  are  indicated, 
while  zinc,  nitrate  of  silver,  copper,  or  other  astringents  are  to  be 
avoided. 


CONJUNCTIVITIS   GRANULOSA. 


199 


(J?)  Conjunctivitis  granulosa  {C.  trachomatosa,  Egyptian  Oph- 
thalmia, Trachoma). — We  have  seen  that  in  conjunctivitis  follicularis 
the  growth  of  follicles  was  a  moderate  one,  and  that  after  a  longer 
or  shorter  period  the  contents  of  the  follicles  was  absorbed,  and 
that  the  follicles  disappeared.  Not  so  in  trachoma.  Here  the 
formation  of  follicles  is  unrestricted,  they  stand  in  regiments 
(/v^.  75),  shoulder  to  shoulder;  the  conjunctiva  dies  where  the 
follicles  are  particularly  numerous,  ulceration  takes  place,  and 
healing  results  only  by  displacing  the  conjunctiva  with  scar  tissue. 

Raehlmann  considers  the  development  of  the  follicles  to  be  the  following :  at  the  be- 
ginning a  follicle  is  a  simple  collection  of  lymph  cells.     The  "  capsule  "  is  only  apparent, 


Fig.  75. — Trachoma.     (After  G.  L.  Johnson.) 


depending  on  the  form  of  the  external  cellular  layers.  These  border  cells  are  changed  to 
spindle-form  cells  {Fig.  76)  and  finally  into  connective  tissue  fibers.  The  numerous 
lymph  corpuscles  that  have  collected  about  the  follicles  suffer  from  the  same  fate  {Fig.  76). 
During  this  process  the  tip  of  the  follicle  has  broken  through  the  conjunctival  epithelium, 
the  cell  contents  has  been  emptied,  and  from  the  bottom  the  usual  wound  granulation 
springs  up  ;  or  the  inner  cells  of  the  follicle  may  be  the  ones  to  change  into  spindle  cells, 
and  thereafter  into  connective  tissue  fibers.  The  amount  of  new  formed  connective  tissue 
is  in  that  case  doubly  abundant.  The  more  common  process  is  the  rupture  and  emptying 
of  the  follicle  ;  the  less  common  is  the  connective  tissue  change  of  its  contents  ;  but  both 
may  happen  in  one  and  the  same  case — ulceration  in  the  superficial,  connective  tissue 
change  in  the  deep  follicle.  Since  this  follicular  formation  is  the  expression  of  a  conjunc- 
tival inflammation,  or  perhaps  is  itself  an  inflammatory  irritant,  it  happens  that  the  areas 
of  the  conjunctiva  which  are  not  strewn  with  follicles,  and  particularly  the  papillary  body, 
hypertrophy.     The  "  papillae,"  that  in  a  healthy  condition  are  extremely  modest,  grow 


200  DISEASES    OF   THE    CON7UNCT1VA. 

into  points  of  arrogant  tufts  and  give  to  the  whole  conjunctiva  the  appearance  of  a  gran- 
ulating surface.  (Pathologists  now  consider  the  change  of  lymph  corpuscles  into  connec- 
tive tissue  fibers  as  most  improbable.) 

Trachoma  is  a  disease  that  consumes  years  in  running  its  course. 
This  means,  therefore,  that  the  symptoms  of  the  patient  and  the 
appearance  of  his  eyes  undergo  many  changes  during  this  period. 
The  various  stages  may  be  perhaps  described  as  different  types  of 
trachoma,  but  if  we  remember  that  the  ulcerating  and  then  the 
cicatrizing  folHcle  are  the  essential  sign  of  trachoma,  that  the  nuin- 
ber  of  nodules  (follicles)  varies  in  different  cases,  that  new  batches 
of  nodules  spring  up  while  the  old  ones  are  ulcerating  or  cicatriz- 
ing, it  is  unnecessary  to  describe  these  various  manifestations  as 
particular  types  of  the  clinical  picture. 

Trachoma,  in  spite  of  its  unusually  chronic  nature,  may  begin 


'-fy'XfR. 


Fig.  76. — Trachoma  Follicle,  with  its  Capsule  in  the  Conjunctiva  Impregnated  with 
Lymph  Corpuscles.    {After  Rcehlmann.) 

in  a  minority  of  cases  as  an  acute  but  severe  conjunctival  inflam- 
mation, with  the  lids  on  that  account  deeply  involved.  They  are 
red  and  swollen;  the  upper  lid  droops  and  cannot  be  raised, — an 
inflammatory  ptosis.  In  the  red  and  swollen  conjunctiva  there  are 
at  first  no  granulations  visible,  and  not  till  the  swelling  of  the  mu- 
cous membrane  recedes  do  they  appear  above  the  surface  to  pre- 
sent a  picture  similar  to  that  of  follicular  catarrh.  There  is  no 
certain  differentiation  in  this  stage  between  trachoma  and  follicular 
catarrh.  The  further  course,  as,  for  example,  the  peculiar  affection 
of  the  cornea  (pannus),  gives  us  the  first  positive  distinction.  How- 
ever, the  diagnosis  may  be  assumed  as  probable  if  we  remember 
that  the  seat  of  trachoma  is  at  the  upper  fornix,  while  follicular 
conjunctivitis  rages  principally  in  the  lower  fornix. 


CONJUNCTIVITIS    GRANULOSA.  20I 

In  the  majority  of  cases  trachoma  develops  as  a  chronic  disease, 
extending  over  several  months.  The  patient  has  very  little  trou- 
ble, often  even  no  suspicion  that  his  eye  is  infected.  If  the  lids 
are  everted,  one  finds  them,  particularly  at  the  upper  fornix,  strewn 
with  numberless  points  from  /  to  ^  mm.  in  diameter,  which  are 
usually  compared  to  cooked  sago  grains  or  to  frog  spawn  ;  they  are 
distinguished  from  the  nodules  of  follicular  catarrh  by  their  more 
noticeable  size,  their  grayer  color,  and  lesser  translucency.  The 
conjunctiva  of  the  lids  is  at  the  same  time  reddened  and  moderately 
swollen,  and  strewn  with  grayish-yellow  dots  {Fig.  75),  about  the 
size  of  a  pin-head,  which  do  not  protrude  above  the  surface.  In 
the  majority  of  cases  the  cornea  is  already  affected  in  a  peculiar 
manner,  this  fact  deciding  in  favor  of  trachoma  and  against  follicu- 
lar catarrh.  This  affection  of  the  cornea  is  called  pannus  trachoma- 
tosus.  It  begins  as  a  new  growth  of  tissue  provided  with  blood- 
vessels {Figs.  86  and  Sj,  pp.  2^1.1,  2^2),  in  consequence  of  which  a 
cornea  with  pannus  is  thicker  than  normal,  rougher,  and  raw,  having 
a  smoky-gray  or  flesh-red  color,  according  to  the  vascular  develop- 
ment in  it.  As  a  rule,  the  upper  third  of  the  cornea  is  affected,  the 
diseased  portion  being  marked  off  from  the  healthy  cornea  by  a 
horizontal  straight  line  {Fig.  8y).  Along  this  line  one  occasionally 
found  shallow  ulcers,  and  nearly  always  small  punctate  infiltrations 
that  lie  with  preference  just  at  the  end  of  a  blood-vessel.  The 
histology  of  pannus  will  be  more  minutely  studied  on  p.  2^1.  The 
first  stage  described  here  is  often  called  granular  trachoma  with 
quite  decided  increase  in  the  symptoms.  The  second  stage  of  tra- 
choma begins  with  ulceration  of  the  follicles  and  with  granulations. 
The  secretion,  till  now  slight,  becomes  muco-purulent,  or  consists 
entirely  of  pus,  and  is  so  abundant  that  the  lashes  mat  together; 
the  lids  appear  as  if  smeared  with  the  wet  or  drying  secretions. 
The  conjunctiva  of  the  bulb  visible  through  the  palpebral  fissure  is 
decidedly  red,  the  cornea,  nearly  without  exception,  hazy  with 
pannus.  If  the  lids  are  everted  we  see  that  some  of  the  follicles 
have  lost  their  characteristic  round  shape  and  in  place  of  them 
we  find  small  crater-like  ulcers,  giving  to  the  surface  a  ragged 
appearance.  Small  blood-red  excrescences,  the  so-called  wound 
granulations,  grow  from  the  bottom  of  these  ulcers  and  form 
the  passage  to  the  third  stage,  that  of  cicatrization.  That  part 
of  the  conjunctiva  not  yet  occupied  by  nodules  (follicles)  is  also 
red  and  swollen,  the  papillary  body  particularly  showing  the  lux- 


202  DISEASES    OF   THE    CONJUNCTIVA. 

urious  growth  that  has  suggested  for  this  stage  the  term  "  papillary 
trachoma." 

If  all  the  follicles  ulcerate  and  become  displaced  by  granulations, 
we  have  a  picture  that  is  scarcely  distinguishable  from  chronic 
blennorrhea.  A  confusion  of  the  two  conditions  is  of  little  conse- 
quence, for  there  is  no  radical  difference  in  their  treatment.  How- 
ever, in  most  cases  of  trachoma  we  should  find  at  this  stage  one  or 
more  characteristic  signs,  such  as  groups  of  follicles,  or  pannus  trach- 
omatosus,  or  the  peculiar  conjunctival  cicatrix  (see  below).  The 
difference  between  trachoma  and  tuberculosis  is  described  on  p.  206. 

The  follicle  growth  is  in  many  cases  so  luxurious  that  the  entire  conjunctiva  seems 
taken  up  by  it.  Individual  granules  cannot  be  seen,  or  at  the  most  they  appear  as  glis- 
tening grayish-yellow  s[X)ts  below  the  surface.  The  mucous  membrane  is  relatively 
smooth,  but  swollen  and  of  a  dirty  red.  The  fornix  is  puffed  out,  the  whole  condition  is 
what  Stellwag  has  called  "pickled  trachoma."  This,  also,  is  followed  by  ulceration, 
the  surface  of  the  conjunctiva  losing  its  smoothness  and  becoming  rough  and  ragged. 
Cicatricial  contraction  is  always  excessive. 

After  the  disease  has  existed  for  months  in  this  second  stage,  it 
passes  gradually  into  the  third  and  last  stage,  cicatrization.  The  ap- 
pearance of  the  patient  is  again  completely  changed.  The  secretion 
dries  up,  or  is  limited  to  a  small  amount  of  glairy  mucus.  The  con- 
junctiva beneath  the  fissure  is  no  longer  inflamed,  but  looks  dry  and 
dirty-white,  thick  and  rolled  into  fine  folds.  This  atrophic  condition 
is  called  Xerosis  par enchyinatosa,dLnd  is  of  much  graver  significance 
than  Xerosis  epithelialis,  to  be  mentioned  later  (/  2ij).  The  lids 
are  also  changed,  the  entire  lid  having  grown  shorter  from  above 
downward,  so  that  in  closing  they  still  gape  to  a  slight  degree. 
The  tarsus  of  the  upper  lid  no  longer  hugs  the  eyeball  but  has  a 
curved  form  of  its  own  easy  to  make  out  when  one  feels  of  it.  The 
posterior  margin  of  the  lid  is  rounded  off  so  that  the  entire  edge 
of  the  lid  is  turned  more  or  less  sharply  inward.  The  lashes  are 
sparse,  broken  off,  and  in  part  bent  inward,  trichiasis.  The  pannus 
has  disappeared  ;  in  favorable  cases  the  blood-vessels  have  atro- 
phied ;  the  round  cells  are  absorbed.  In  other  cases  a  cicatricial 
connective  tissue  has  been  formed  that  produces  an  incurable  cloud- 
iness on  the  cornea.  If  the  upper  lid  is  everted,  a  thick  white  scar 
is  seen  on  its  inner  surface,  which  runs  parallel  to  the  edge  of  the  lid 
^  to  J  /«;«.  from  it ;  this  scar  is  broadest  and  thickest  in  the  middle 
of  the  lid,  from  which  it  sends  out  rays  in  all  directions.  In  other 
cases  the  changes  produced  by  this  scar  are  severest  at  the  fornix,  or 
they  may  form  a  bridge  of  adhesions  between  the  lid  and  the  eyeball. 


CONJUNCTIVITIS    GRANULOSA.  203 

In  spite  of  its  frequency  and  in  spite  of  numerous  and  painstaking  investigations,  the 
nature  of  trachoma  is  not  as  yet  so  clear  as  that  of  blennorrhea.  There  is  not  even 
unanimity  concerning  its  infectiousness.  The  fact  that  trachoma  is  epidemic  in  barracks, 
schools,  and  among  sailors  is  claimed  by  some  as  a  proof  of  its  infectiousness,  but  by 
others  as  a  proof  of  its  myasmatic  nature.  The  regular  involvement  of  both  eyes  is  by 
some  called  an  illustration  of  its  infectiousness  ;  the  rare  but  well-authenticated  cases  of 
one-sided  trachoma  are  used  as  illustration  against  it.  In  spite  of  all  this  we  can  say 
with  Snemisch,  H.  Cohn,  and  others,  that  the  trachomatous  secretion  is  infectious,  not 
through  the  air,  like  measles  and  small-pox,  but  by  direct  contagion.  This  infection 
happens,  as  a  rule,  after  the  common  use  of  handkerchiefs,  wash-bowls,  and  towels,  or 
by  the  contact  implied  when  the  well  and  the  sick  sleep  together. 

As  we  view  the  matter  to-day,  we  are  inclined  to  assume  that  some  specific  germ  is 
the  cause  of  trachoma.  Investigation  directed  to  discover  this  trachoma  germ  has  given 
results  that  are  not  quite  harmonious.  This  may  be  said,  too,  of  the  germ  of  follicular 
conjunctivitis.  The  question  is  not  yet  solved  whether  trachoma  and  follicular  catarrh 
are  different  diseases.  Many  investigators  assume  that  the  same  germ  may  produce  at 
one  time  a  mild  disease  called  follicular  catarrh,  and  at  another  a  severe  disease  called 
trichoma.  Indeed,  many  imagine  that  chronic  blennorrhea  is  a  third  leaf  on  the  same 
tree,  and  that  the  gonococcus  of  Neisser  is  the  ultimate  cause  of  them  all.  This  view 
finds  support  from  the  observed  fact  that  contagion  of  a  healthy  conjunctiva  from  pus  of 
a  chronic  blennorrheal  conjunctivitis  will  in  certain  cases  produce  a  trachoma  and  not  a 
blennoiThea.  The  demonstration  is  not  a  perfect  one,  since  the  secretion  of  a  chronic 
blennorrhea  is  undoubtedly  the  home  of  many  kinds  of  germs.  The  view  finds  no 
support  from  the  fact  that  individuals  differ  in  the  resistance  to  trachoma,  and  that  tra- 
choma is  limited  to  well-defined  regions,  which  is  not  at  all  the  case  with  blennorrhea 
and  gonorrhea.  The  view  that  trachoma  and  follicular  catarrh  are  the  same  is  moreover, 
actually  denied.  Foerster  and  H.  Cohn  consider  it  only  a  question  of  time  when  the 
individuality  of  each  disease  will  be  recognized  by  all  surgeons.  There  remains  only  one 
fact  more  to  be  mentioned  :  that  another  germ  altogether,  which  no  one  has  as  yet  called 
the  real  trachoma  b.icterium  (that  is,  the  tubercle  bacillus),  is  able  to  produce  a  typical 
clinical  picture  of  trachoma  in  its  second  stage  (/.  206). 

As  a  rule,  young  persons  in  the  second  or  third  decade  of  life  are  more  inclined  to 
trachoma.  The  poor  are  oftener  attacked  than  those  in  comfortable  circumstances,  a 
fact  easily  explained  by  the  greater  care  and  cleanliness  of  the  latter.  Poorly  nourished 
persons,  those  suffering  from  scrofula  and  tuberculosis,  are  said  to  supply  a  relatively 
large  numl)er  of  cases  of  severe  trachoma.  Negroes  are  said  to  be  nearly  immune.  Tra- 
choma is  a  disease  of  low  lands,  flat  coast  districts,  and  river  valleys.  Elevated  regions 
are  free  from  it.  Here  in  ZUrich,  trachoma  is  rare  ;  in  the  Baden  Oberland  it  is  infre- 
quent, but  near  the  mouth  of  the  Main  it  is  seen  oftener,  and  from  there  downward  in 
the  Rhine  Valley  it  increases  till  it  reaches  its  greatest  luxuriance  at  the  mouth  of  that 
river.  Two  hundred  meters  above  sea  level  trachoma  loses  its  contagiousness  to  a  certain 
extent,  although  many  elevated  districts  become  infected  by  the  numerous  immigration  of 
trachoma  cases.  If  a  trachoma  patient  travels  to  a  dry  altitude  his  disease  runs  a  com- 
paratively rapid  and  favorable  course. 

The  prognosis  is  unfavorable.  To  be  sure,  a  cure  may  take 
place,  but  after  such  a  long  delay,  and  after  such  an  abundant  pro- 
liferation of  granules,  that  all  the  conjunctival  ti.ssue  capable  of 
producing  them  has  been  destroyedand  replaced  by  cicatricial  tissue. 


204  DISEASES    OF   THE    CONJUNCTIVA. 

The  resulting  condition,  the  xerosis  of  the  conjunctiva,  is  of  itself 
the  source  of  many  disturbances. 

Normal  conjunctiva  is  moist  and  smooth,  for  the  reasons  that  the  gentle  irritation  of 
conjunctiva  on  cornea  is  reflexly  a  cause  of  the  secretion  of  tears,  and  that  the  conjuncti- 
val glands  themselves  secrete  a  small  amount  of  mucus.  Xerosis  cuts  off  both  supplies 
of  moisture  by  closing  the  ducts  of  the  lacrimal  gland  with  a  scar,  and  by  destroying  the 
glandular  cells  lying  in  the  bed  of  the  conjunctiva. 

The  dryness  of  the  conjunctiva  is  very  disagreeable  to  the  patient, 
and  leads  to  a  certain  distress  in  all  movements  of  lids  and  eyes. 
It  induces,  moreover,  a  change  (a  dryness)  in  the  corneal  epithe- 
lium, vi^hich  is  of  direct  influence  on  the  visual  power.  Entropium 
and  trichiasis  are  also  immediate  results  of  cicatricial  contraction, 
and  modify  vision  materially.  The  consequence  is  that  the  disease 
attacks  the  cornea  directly,  and  in  the  great  majority  of  all  cases 
enfeebles  the  vision  by  incurable  corneal  opacities.  In  some  cases 
the  prognosis  depends  on  the  greater  or  less  abundance  of  granu- 
lations formed,  and  on  the  treatment. 

Treatment,  taken  altogether,  is  encouraging,  and  would  have 
even  more  successful  results  if  it  were  not  impossible  for  many 
patients  to  continue  it  as  long  as  may  be  necessary.  Treatment 
should  begin  by  telling  the  patient  of  the  infectiousness  of  the  dis- 
ease and  of  the  usual  sources  of  infection,  as  towels,  handkerchiefs, 
etc. ;  the  proper  advice  (often  ignored)  as  to  cleanliness  of  rooms 
and  clothing  should  be  given.  If  the  patient  is  scrofulous  or  tuber- 
culous, his  habits  of  life  should  be  made  as  favorable  as  possible. 
It  is  a  good  plan  to  send  patients  to  a  high  altitude,  although  this 
is  often  impossible,  since  the  poor  are  usually  the  victims  of  tra- 
choma and  the  ones  who  apply  for  treatment.  For  local  treatment 
there  are  numberless  applications.  I  shall  discuss  here  only  those 
best  approved, — copper,  surgical  treatment,  and,  the  latest  method, 
massage  with  sublimate  solution. 

The  copper  pencil  is  suitable  for  both  first  and  second  stages.  It 
is  applied  by  everting  the  upper  lid  and  rubbing  the  polished  pencil 
gently  into  the  fornix  first,  and  on  the  back  of  the  lid  afterward. 
Ripe  granules  are  broken  and  their  contents  thereby  squeezed  out. 
The  effect  of  this  is,  as  a  rule,  quite  favorable,  both  to  the  granules 
and  papillae,  as  well  as  to  the  pannus.  Small  corneal  ulcers  oppose 
no  obstacle  to  it,  and  heal  quickly  after  the  copper  application.  If 
the  discharge  is  a  very  abundant  pus,  however,  nitrate  of  silver  in 
two  per  cent,  or  five  per  cent,  solution  can  be  used.     This  cautery 


CONJUNCTIVITIS    GRANULOSA.  205 

with  blue  stone  (the  copper  sulphate  pencil)  may  be  daily  repeated. 
Many  patients  who  cannot  visit  the  physician  every  day,  learn  to 
make  the  application  themselves.  As  a  rule,  its  effect  passes  off  in 
the  course  of  time  and  improvement  ceases,  and  some  new  remedy 
must  be  then  tried. 

In  case  the  surface  of  the  mucous  membrane  hypertrophies, 
which  would  obviate  the  fear  of  conjunctival  contractions,  excision 
of  the  redundant  folds  of  the  fornix  may  be  practised — strips  of 
conjunctiva  /oto  /j  nini.  long  and  2  to  j  mm.  broad  being  removed 
without  fear ;  many  surgeons  cut  out  pieces  j  cm.  long  and  0.6  cm. 
broad,  including  sections  of  the  tarsus  !  The  wound  should  be 
carefully  sutured.  A  noticeable  improvement  generally  follows  this 
excision.  For  pannus  we  have  another  surgical  expedient;  assum- 
ing that  pannus  depends  on  a  purely  mechanical  cause,  the  scratch- 
ing of  the  granules  on  the  cornea,  it  has  been  proposed  to  counter- 
act this  by  splitting  the  external  canthus.  Pannus  is  by  no 
means,  however,  traceable  in  every  case  to  mechanical  irritation, 
although  undeniable  influence  on  the  disappearance  of  pannus 
must  be  ascribed  to  the  effect  of  thus  relaxing  the  tension  of  the 
upper  lid. 

The  latest  method  is  that  of  Keining.  It  consists  in  a  firm  mas- 
sage to  the  exposed  conjunctiva  of  the  upper  lid  with  a  wad  of 
cotton  soaked  in  i  :  2000  sublimate  solution.  To  reach  the  fornix 
the  everted  lid  must  be  still  further  turned  over,  while  the  patient 
looks  downward  as  much  as  possible.  The  dryer  and  harder  the 
granules  and  hypertrophies  of  the  conjunctiva  are,  the  firmer  should 
the  rubbing  be  ;  while  the  more  hyperemic  and  softer  the  conjunc- 
tiva, the  more  gently  must  it  be  handled.  The  results  of  this 
method  are  most  encouraging,  according  to  v.  Hippel.  The  gran- 
ules recede  without  leaving  scars ;  pannus,  small  ulcers,  and  infil- 
trates are  quick  to  heal,  and  the  time  required  for  treatment  is 
much  shorter  than  by  the  other  methods.  Relapses  or  sequelae 
are  not  prevented  by  it,  but  they  heal  very  quickly  when  the 
method  is  again  used. 

I  prefer  massage  with  iodoform  powder  to  that  with  sublimate  solution.  The  powder 
does  not  leave  behind  the  ugly  gray  coating  that  may  on  the  following  day  demand  a 
postponement  of  the  treatment.     Iodoform  massage  is  also  less  painful  to  the  patient. 

Distorted  positions  of  the  lids  and  lashes  must  be  treated  accord- 
ing to  the  principles  on  /.  16^.  Corneal  opacities,  depending  on 
pannus,  if  they  are  still  capable  of  absorption,  are  to  be  treated  by 


206  DISEASES    OF    THE    CONJUNCTIVA. 

massage.     The  discomforts  of  an  atrophied  conjunctiva  (xerosis) 
are  lessened  by  the  use  of  milk  as  an  application. 

(c-)  Conjunctivitis  tuberculosa. — The  resemblance  of  this  disease  to  trachoma  is 
so  great  that  the  differences  should  be  specially  mentioned.  In  tuberculosis  there  are 
follicles,  papillary  hypertrophies,  ulcers,  and  pannus  ;  but  while  cicatrization  and  heal- 
ing does  result  in  trachoma,  in  tuberculosis,  on  the  other  hand,  the  ulceration  and  the 
hypertrophy  continue  unlimitedly  and  end  finally  in  complete  destruction  of  the  surface 
of  the  eyeball.  Tuberculosis  is  therefore  a  still  more  dangerous  enemy  than  trachoma, 
and  it  is  of  importance  in  choosing  the  treatment  to  differentiate  it  clearly  from  trachoma. 
This  is  not  easily  done,  and  has  been  made  possible  only  within  a  recent  period. 
The  diagnosis  depends  upon  the  following  facts :  Trachoma  attacks  both  eyes  as  a 
rule  ;  tuberculosis,  on  the  other  hand,  is  almost  always  confined  to  one  eye,  and  if,  as 
in  a  case  of  my  own,  it  does  appear  in  both  eyes,  the  stage  of  the  disease  is  so  different 
in  each  eye  that  this  very  difference  simplifies  the  recognition  of  the  picture.  The  swell- 
ing of  the  lymph  glands  in  front  of  and  beneath  the  ear  and  on  the  neck  as  far  as  the 
chin,  is  very  noticeable  in  tuberculosis,  and  sometimes  there  may  even  be  suppuration 
from  them  ;  but  in  trachoma,  especially  in  mild  cases,  these  lymph  glands  play  a  very 
modest  role.  The  ulcers  in  tuberculosis  are  decidedly  greater  than  in  trachoma.  Fi- 
nally, it  indicates  tuberculosis  if  there  are  hypertrophies  in  the  lacrimal  sac  and  in  the 
nose. 

The  conditions  mentioned  here  arouse  the  suspicion  of  tuberculosis  ;  the  proof  of  it  is 
supplied  only  by  the  histological  and  bacteriological  demonstration  of  tubercle  bacilli  in 
the  secretions  of  the  tissues. 

The  disease  results  from  inoculation  of  the  tubercle  bacillus  on  the  conjunctiva.  In 
one  case  the  patient  himself  provides  this  inoculation  by  rubbing  his  eyes  with  fingers 
that  are  soiled  with  some  tubercular  poison,  like  the  sputum.  In  another  case  the  disease 
may  spread  from  the  nose  through  the  tear  sac  on  to  the  conjunctiva.  In  a  third  case  a 
foreign  body  may  be  the  carrier  of  the  disease.  Fuchs  has  observed  that  the  favorite 
seat  of  a  foreign  body  beneath  the  upper  lid  (about  2  mm.  from  the  posterior  margin)  is 
often  the  initial  spot  to  be  infected  with  tuberculosis. 

The  prognosis  is  very  unfavorable.  Left  to  itself,  the  disease  leads  to  destruction  of 
the  eyeball.  Not  only  does  the  whole  cornea  grow  opaque  with  pannus,  but  the  sclera 
itself  becomes  saturated  with  tubercle  and  granulations  until,  finally,  the  eyeball  atrophies 
and  the  condition  of  phthisis  bulbi  is  produced.  If  an  early  and  appropriate  treatment 
is  begun,  a  cure  may  be  effected  in  some  cases  and  an  improvement  in  others. 

Treatment,  like  that  of  tuberculosis  in  other  parts  of  the  body,  is  both  general  and 
local.  The  general  treatment  consists  in  life  in  the  pure,  open  air,  care  of  the  skin,  and 
abundant  nourishment.  The  local  treatment  must  effect  the  destruction  of  all  tissue  in- 
volved. The  boldness  of  surgical  interference  must,  however,  be  modified  by  the  fear 
of  producing  too  great  a  scar,  with  its  consequent  disasters.  According  to  Haab's  ex- 
perience, the  best  plan  is  to  remove  all  comb-like  excrescences  and  growths  with  knife 
and  scissors,  to  curette  ulcers  with  a  sharp  spoon,  and  to  destroy  small  punctate  and 
nodular  foci  with  the  actual  cauteiy.  All  this,  as  a  rule,  cannot  be  done  at  one  time,  but 
must  be  extended  through  several  operations. 

3.  CIRCUMSCRIBED  DISEASES. 
{a)  Conjunctivitis  catarrhalis  estiva  {Hypertrophia  epithelialis  estiva,  Phlyctena 
pallida). — This  disease  forms  a  bridge,  so  to  say,  to  that  group  of  diseases  having  their 
principal  seat  on  the  conjunctiva  of  the  eyeball.     The  changes  produced  by  spring  catarrh 


CONJUNCTIVITIS    PHLYCTENULOSA.  20/ 

lie  chiefly  at  tlie  "  limbus,"  that  is,  at  the  spot  where  the  conjunctiva  passes  over  into  the 
cornea,  but  in  the  majority  of  cases  there  is  at  the  same  time  a  similar  involvement  of  the 
conjunctiva  of  the  upper  lid.  The  disease  attacks  both  eyes,  preferably  of  country  chil- 
dren from  five  to  fourteen  years  old.  It  appears  in  the  spring  with  the  beginning  of  warm 
weather,  continues  with  slight  changes  about  the  same  through  the  summer,  subsides 
gradually  in  the  fall,  and  appears  again  in  full  activity  the  next  spiing.  To  this  pecu- 
liarity is  due  the  name  of  "Spring  catarrh."  The  patient  complains  of  a  pricking  pain, 
photophobia,  and  a  moderate  "  weeping  "  or  secretion  of  tears,  with  light,  stringy  mucus. 
On  examination,  the  surgeon  first  notices,  as  a  rule,  a  sleepy  look,  that  is,  a  very  slight 
droop  of  the  upper  lid.  In  the  fissure  a  few  large  blood-vessels  are  visible,  which  course 
from  the  canthus  toward  the  cornea,  to  sink  into  the  grayish  and  swollen  limbus.  The 
limbus  injection  appears  in  various  characters ;  at  one  time  a  jelly-like  band  surrounding 
the  cornea,  at  another  a  chain  of  dots,  red  in  the  fissure  but  pale  above  and  below  ;  or 
this  limbus  injection  may  be  limited  to  the  fissure,  forming  two  triangles  with  bases  on 
the  cornea  and  apexes  pointing  toward  the  inner  and  outer  canthus.  If  the  lids  are 
everted  a  second  sign  of  the  catarrh  will  be  noticed,  the  soft  and  pale  appearance  of  the 
whole  conjunctiva  ;  it  looks,  says  Horner,  as  if  it  were  covered  with  a  thin  film  of  milk. 
The  third  diagnostic  sign  is  a  hypertrophic  growth  of  the  conjunctiva  of  the  upper  lid. 
At  one  time  there  are  only  a  few  flat,  pale  protuberances  sitting  on  a  thin  trunk,  like 
mushrooms,  or  again  there  are  so  many  of  them  that  they  crowd  against  each  other,  being 
separated  only  by  delicate  furrows.  These  hypertrophies  have  often  led  to  confusion 
between  spring  catarrh  and  trachoma,  but  the  lack  of  follicles  and  the  freedom  of  the 
cornea  from  involvement  should  prevent  such  a  confusion. 

The  essence  of  the  disease  is  a  pronounced  thickening  of  the  epithelium  and  a  round 
cell  infiltration  of  the  tunica  propria  conjunctivae  ;  a  new  growth  of  connective  tissue  is 
found  later.  The  thickening  of  the  epithelium  is  the  reason  for  the  peculiar  soft,  white 
discoloration  of  the  mucous  membrane. 

The  prognosis  is  favorable,  even  though  the  disease  may  last  for  years  ;  Horner  men- 
tions a  man  twenty-five  years  old,  "  who  has  had  this  '  Easter  present '  since  his  thirteenth 
year."  But  after  the  disease  has  exhausted  its  strength,  nothing  remains  behind  except 
a  feeble  discoloration  of  the  mucous  membrane,  some  furrows  on  the  inner  surface  of  the 
lid,  and  in  a  few  cases  an  opacity  of  the  edge  of  the  cornea. 

Treatment  is  practically  futile.  Astringents  and  stimulants  are  poorly  borne  ;  exci- 
sion or  cautery  of  the  hypertrophies  are  well  borne,  but  the  result  from  them  is  seldom  a 
lasting  one.  The  best  plan  is  to  use  a  mild  eye-water  [Zinc  stilfat.  or  Plumb,  acet., 
O.I  to  jo.o),  and  to  insist  on  suitable  habits  for  the  patient,  such  as  avoidance  of  smoke, 
dust,  or  hot  and  drafty  rooms.     Protective  glasses  must  be  prescribed. 

{b)  Conjunctivitis  phlyctenulosa  {Eczematosa,  Scrophulosa 
lymphatica,  Eczema  of  the  Conjunctiva). — This  disease  is  charac- 
terized by  the  eruption  of  temporary  vesicles  and  pustules  (phlyc- 
tenules). These  phlyctenules  are  always  on  the  conjunctiva  bulbi, 
but  may  be  of  different  sizes  and  of  varying  distances  from  the 
cornea.  Two  types  of  eczema  are  therefore  described.  One  is 
called  by  Horner  the  solitary  form ;  it  begins  so  quietly  at  times 
that  the  patient  does  not  notice  it,  and  has  his  attention  called  only 
to  the  redness  of  his  eye.  In  other  cases  the  development  of  the 
pustules  or  of  one  pustule  begins  with  a  pricking  pain,  photophobia, 


208  DISEASES    OF    THE    CONJUNCTIVA. 

and  lacrimation.  The  vesicles  form  flattened  prominences  of  from 
I  to  4  mm.  in  diameter ;  their  color  is  grayish-red  and  noticeably 
paler  than  the  deep  red  surroundings.  The  light  red  conjunctival 
vessels  can  be  distinguished  from  the  bluish  episcleral  vessels 
shimmering  below  them.  The  reddened  mucous  membrane  is  only 
moderately  congested  and  passes  gradually  into  healthy  tissue. 
The  vesicle  consists  of  a  collection  of  round  cells  beneath  unaffected 
epithelium.  This  epithelium  is,  as  a  rule,  cast  off  after  a  few  days, 
and  the  vesicle  becomes  an  ulcer  which  rapidly  flattens  out,  while 
epithelium  is  developed  above  it  from  its  edges.  As  the  epithelial 
covering  is  reproduced  the  inflammation  declines  by  degrees  from 
the  edges  toward  the  center,  so  that  after  a  week  or  so  only  a  red- 
dened point  can  be  seen  at  the  spot  of  the  healing  phlyctenule. 
Single  (solitary)  phlyctenules  grow,  as  a  rule,  in  the  path  of  the 
fissure,  a  few  millimeters  from  the  margin  of  the  cornea,  being 
seldom  found  within  the  cornea  itself.  The  disease  is  serious  only 
when  phlyctenules  are  too  near  the  cornea.  When  present  on  the 
conjunctiva  they  heal  without  a  trace,  but  when  on  the  cornea 
there  is  usually  some  opacity  left  behind. 

The  second  form  is  called  the  miliary  or  multiple.  It  develops 
usually  with  signs  of  decided  irritation,  severe  pain,  photophobia, 
and  even  spasm  of  the  lid.  The  lid  is  swollen  and  red ;  the  injec- 
tion of  the  eye  is  severe  and  extensive  ;  the  limbus  conjunctivae  is 
swollen  and  strewn  with  minute  phlyctenules  that  look  like  grains 
of  sand.  If  the  lid  is  everted  its  conjunctiva  is  swollen,  velvety, 
and  red.  There  is  an  abundant  muco-purulent  discharge,  which  is 
lacking  in  nearly  every  case  of  the  solitary  form.  The  course  of 
the  miliary  form  is  extremely  rapid.  The  disease  soon  reaches  its 
height,  remains  unchanged  for  a  few  days,  and  then  as  rapidly  dis- 
appears, either  with  or  without  ulcers. 

This  eczemaof  the  conjunctiva  usually  attacks  children  from  four 
to  fourteen  years  old,  although  it  may  occasionally  be  seen  in 
adults.  Scrofulous  children  are  particularly  victims,  that  is,  chil- 
dren who  suffer  from  eczema  of  the  upper  lip  or  nose,  of  the  skin 
near  the  eyes  or  behind  the  ears,  and  of  the  scalp  ;  and  also  those 
who  have  swollen  glands  behind  and  below  the  jaw,  and  who  suffer 
from  catarrhs  of  other  mucous  membranes,  particularly  that  of  the 
nose.  The  miliary  form  attacks  also  children  who  have  just 
recovered  from  measles  or  scarlet  fever.  Eczema  of  the  conjunctiva 
attacks  one  or  both  eyes ;  or  it  may  change,  healing  in  one  eye 


CONJUN'CTIVITIS    PHLYCTENULOSA.  2O9 

while  it  breaks  out  afresh  in  the  other.  The  disease  has  a  decided 
tendency  to  relapse,  so  that  it  may  last  for  years,  although  each 
attack  runs  its  course  in  about  fourteen  days.  It  is  not  contagious, 
for  admitting  that  inoculation  of  the  secretion  in  a  healthy  eye 
produces  inflammation,  this  is  not  an  eczema  unless  the  healthy 
eye  happens  to  belong  to  an  eczematous  person.  The  facts  just 
mentioned  support  the  assumption  that  the  disposition  to  conjunc- 
tival eczema  lies  in  an  unhealthy  nature  of  the  whole  body  (scrofu- 
losis),  on  account  of  which  only  a  comparatively  slight  irritation  is 
necessary  to  excite  this  conjunctivitis.  ^That  external  irritation 
plays  its  part  is  proved  by  the  fact  that  the  area  of  the  fissure  is 
preferably  the  portion  attacked  ;  but  whatever  may  be  the  nature  of 
this  irritation  cannot  as  yet  be  stated. 

Burckhardt  has  cultivated  various  kinds  of  cocci  from  phlyctenules,  staphylococcus 
pyogenes  aureus,  albus,  and  flavus. 

He  considers  these  cocci  to  be  the  cause  of  the  conjunctival  (and  corneal)  eczema, 
because  he  has  succeeded  in  producing  a  typical  corneal  eczema  by  inoculating  rabbits 
with  them.  Bach  has  confirmed  these  statements  as  far  as  the  staphylococcus  pyogenes 
aureus  is  concerned,  and  has  produced  phlyctenules  by  inoculation  in  human  beings  as 
well. 

Since  staphylococci  are  found  with  extraordinary  frequency  on  the  healthy  conjunctiva 
and  lids,  there  would  be  no  lack  of  opportunity  for  infection.  It  is  still  necessary  to 
explain  how  the  infection,  or  the  loss  of  epithelium  necessary  for  it,  can  take  place.  This 
explanation  is  difficult  to  give,  particularly  for  a  case  of  corneal  phlyctenule  (/.  2jj)  or 
groups  of  them,  the  cornea  being  protected  from  minute  injury  not  only  by  its  many 
layers  of  epithelium,  but  also  by  a  rich  nerve  supply  and  the  accompanying  sensitiveness. 
Again,  we  often  see  severe  injury  to  the  corneal  epithelium  without  the  least  sign  of  a 
phlyctenule.  In  short,  even  if  the  staphylococcus  be  guilty  of  arousing  a  conjunctival  or 
corneal  eczema,  there  will  still  be  one  missing  link  in  the  chain  of  a  complete  demonstra- 
ble explanation. 

The  prognosis  is  favorable  so  long  as  the  eruption  is  confined  to 
the  conjunctiva.  This  is  by  no  means  always  the  case.  On  the 
contrary,  the  disease  has  a  decided  tendency  to  break  out  on  the 
cornea,  or  to  pass  to  the  cornea  from  the  conjunctiva  (/>.  2ji). 

In  both  cases  a  corneal  scar  may  remain,  this  being  obviously 
worse  for  vision  in  proportion  to  its  size  and  its  closeness  to  the 
center  of  the  cornea.  In  making  a  prognosis,  the  great  tendency 
to  relapse  must  be  considered,  but  the  prognosis  may  still  be  favor- 
able, because  treatment  shows  good  results,  as  a  rule. 

Treatment  must  be  general  and  local.  Unfortunately,  general 
treatment  is  hard  to  carry  out,  owing  to  the  poverty,  ignorance,  or 
prejudice  of  the  parents.  Baths,  that  is,  general  cleanliness  of  the 
14 


2IO  DISEASES    OF   THE    CONJUNCTIVA. 

child,  should  be  ordered,  and  life  in  the  open  air  (not  in  a  dark 
room  !),  or  at  least  in  well-ventilated  rooms,  with  open  windows  at 
night,  and,  finally,  good  food — like  meat,  eggs,  milk,  butter,  or  cod- 
liver  oil.  All  this  will  not  cure  a  case,  but  it  will  encourage  healing 
and  help  to  prevent  relapses. 

Local  treatment  should  be  stimulating.  Its  effects  are  noticed 
quite  rapidly.  The  most-used  remedies  are  calomel  and  yellow 
mercurial  ointment.  The  calomel  must  be  absolutely  dry  and 
powdery,  and  should  be  dusted  with  a  camel's-hair  brush  onto  the 
conjunctiva  once  a  day,  while  the  under-lid  is  drawn  down.  The 
lids  form  little  strings  of  this  dust  which  lie  for  hours  in  the  upper 
fornix.  When  the  calomel  (HgjCla)  is  brought  into  contact  with 
the  sodium  chlorid  _of  the  tears,  it  is  changed  into  the  bichlorid 
(HgCl2),  to  whose  disinfectant  power  the  favorable  effect  is  ascribed. 
Calomel  must  never  be  used  when  the  patient  is  taking  iodid  of  potas- 
sium, for  if  it  is  so  used  there  will  be  a  formation  of  iodid  of  mer- 
cury, which  is  irritating  to  the  mucous  membrane.  Indeed,  even 
if  no  iodid  of  potassium  has  been  given  at  all,  calomel  may  occa- 
sionally slightly  irritate  the  mucous  membrane.  The  second  stim- 
ulating application,  oxid  of  mercury,  is  called  Pagenstecher's  salve, 
and  should  be  used  once  a  day  in  connection  with  massage.  I 
prefer  this  method  to  the  calomel  treatment,  because  children  very 
soon  learn  to  get  rid  of  calomel  by  rubbing  the  eyes  with  their 
hands  and  by  the  accompanying  flood  of  tears. 

These  remedies  should  be  used  every  second  day  for  weeks  after 
the  eczema  has  disappeared,  to  prevent  relapses.  As  a  rule,  how- 
ever, the  parents  do  not  bring  the  children  after  the  eye  appears 
cured  or  looks  white;  only  when  a  relapse  occurs  do  they  come 
back,  and  then  it  must  be  all  gone  over  again.  If  the  eye  is  irri- 
tated, as  may  often  happen  in  the  miliary  form,  atropin  should  be 
used,  and  daily  massage  with  iodoform  salve  (/ .•  lo),  Pagenstech- 
er's salve  being  applied  when  the  inflammation  is  past.  If  the  ad- 
jacent mucous  membrane  is  swollen,  and  if  a  secretion  is  present,  a 
zinc  wash  {2 :  joo)  may  be  applied.  Here  and  there  cases  occur 
where  the  conjunctival  congestion  is  so  great  and  the  discharge  so 
profuse  that  applications  of  nitrate  of  silver  {2  :  100)  are  unavoida- 
ble. I  then  massage  one  day  with  "  yellow  ointment,"  and  on  the 
next — always  in  the  forenoon — use  the  nitrate  of  silver,  while  in 
the  afternoon  of  each  day  I  apply  the  zinc. 

Stimulants  are  inadmissible  if  corneal  ulcers  are  present  (see  p. 
233)- 


PINGUECULA PTERYGIUM. 


21  I 


^^ 


^^^B^x 


{c)  Pinguecula. — On  those  triangular  areas  of  the  bulb  that  are 
seen  adjacent  to  the  cornea  beneath  the  fissure,  there  are  often 
found  in  old  persons  small,  yellow,  irregular  elevations.  Such  a 
growth  is  called  pinguecula  because  the  yellow  color  deludes  one 
into  supposing  it  to  be  a  fat  tumor.  Histological  examination  has 
shown  that  it  is  only  thickened  epithelium  and  thickened  connec- 
tive tissue,  poorly  supplied  with  blood-vessels.  This  lack  of  vessels 
is  particularly  noticeable  when  the  eye  is  hyperemic,  because  the 
colorless  spot  is  then  sharply  defined  from  its  reddened  surround- 
ino-s.  Pinguecula  is  oftener  to  the  inner  than  to  the  outer  side  of 
the  cornea.  Its  origin  is  obscure.  We  can  suppose  that  some  part 
is  played  by  mistreatment,  to  which  this  portion  of  the  conjunctiva 
is  quite  exposed.  Mechanical  action  of  the  lids  may  also  be  men- 
tioned, by  which  the  redundant  conjunctiva  in  the  palpebral  fissure 
is  made  to  bunch  up  into  little 
folds.  There  is  seldom  any 
pain  from  pinguecula,  and  the 
discomfort  is  hardly  enough  to 
necessitate  the  physician's  in- 
terference. Pinguecula  has  a 
certain  significance  as  being 
an  indirect  course  of  ptery- 
gium. 

{d)  Pterygium. — This  name 
is  used  to  denote  a  triangular- 
shaped  conjunctival  fold,  lying 

with  its  apex  on  the  cornea  and  its  base  toward  the  equator 
of  the  eyeball  {Fig:  77).  The  name  arises  from  the  fact  that 
the  blood-vessels  of  a  pterygium  bear  a  certain  resemblance  to 
the  delicate  vessels  in  an  insect's  wing.  Three  parts  are  dis- 
tinguished— head,  neck,  and  body.  The  head  is  the  point  of 
the  pterygium  turned  toward  the  cornea;  the  neck  is  the  part 
which  lies  at  the  border  between  cornea  and  sclera,  while  the 
remainder  is  termed  the  body.  Although  pterygium  is  adherent 
by  its  under  surface  to  what  lies  beneath,  it  is  possible  to  push  a 
sound  below  the  edges  of  the  neck,  since  they  overhang  somewhat. 
Pterygium  always  grows  beneath  the  palpebral  fissure  and  to  the 
inner  side  of  the  cornea.  At  times  pterygia  grow  on  both  sides  of 
the  same  eye,  one  from  the  inner  and  one  from  the  outer  side.  It 
is   said   that  pterygium   never  grows  on  the  outside  of  the  cornea 


Fig.  77. — Pterygium.     (After  Sichel.) 
The  "  Head  "  reaches  nearly  to  the  pupillary  area. 


212  DISEASES    OF   THE    CONJUNCTIVA. 

alone.*  The  appearance  is  different  according  to  its  age.  A  new 
pterygium  is  thin  and  pale,  only  the  head  being  thick  and  some- 
what raised  above  the  surface  of  the  cornea.  As  it  continues  to 
grow  the  pterygium  becomes  thick  and  red,  so  that  it  looks  like  a 
mass  of  flesh  (pterj^gium  carnosum).  In  the  course  of  years  the 
tissue  atrophies,  and  the  pterj'gium  looks  pale,  thin,  and  tendinous. 

Histological  examination  teaches  that  pterj^gium  consists  of 
nearly  unchanged  conjunctiva  supplied  with  numerous  thin-walled 
blood-vessels.  On  the  cornea  it  takes  the  place  of  epithelium  and 
of  Bowman's  membrane. 

Pterygium  gives  trouble  only  in  case  its  development  is  excess- 
ive, since  in  growing  it  drags  toward  the  cornea  not  only  the  con- 
junctiva of  the  eyeball,  but  also  the  plica  semilunaris  and  even  the 
caruncle,  and  consequently  irritates  the  conjunctiva  mechanically. 
If  this  dragging  is  very  great  it  may  even  act  as  an  obstacle  to 
certain  movements  of  the  eye,  and  therefore  cause  squint  and  diplo- 
pia in  certain  directions  of  vision.     (See  paralytic  squint^ 

The  origin  of  pterygium  has  been  until  now  explained  as  follows :  Some  ulcer  has 
developed  at  the  edge  of  the  cornea,  and  if  the  conjunctiva  was  relaxed  and  yielding,  as 
is  often  the  case  in  elderly  persons,  the  healing  of  the  ulcer  produces  a  fold  of  the  mucous 
membrane  where  it  was  dragged  on.  In  other  cases  a  pinguecula  may  have  been  the 
exciting  cause,  by  growing  over  onto  the  cornea  and  forming  a  crevice,  in  which  small 
foreign  bodies,  dust,  mucus,  or  bacteria  might  lodge  without  being  washed  away  by  the 
movements  of  the  lids.  All  conditions  would  then  be  favorable  to  the  development  of  a 
corneal  ulcer,  the  healing  of  which  would  lead  to  adhesions  between  both  suppurating 
edges,  that  of  the  cornea  and  that  of  the  conjunctiva.  As  long  as  this  crevice  remains 
there  is  always  danger  of  a  new  ulcer,  and  consequently  the  head  of  the  pterygium  grows 
toward  the  center  of  the  cornea,  and  drags  the  neck  and  body  after  it  like  the  tail  of  a 
comet.  Stationary  pterygia  therefore  follow  an  injury  or  an  ulcer,  while  creeping 
pterygia  follow  a  pinguecula. 

The  explanation  of  pterj'gium  just  given  has  been  tested  by  E.  Fuchs  in  an  exhaustive 
manner,  and  found  to  be  untenable.  According  to  him,  pterj'gia  resulting  from  corneal 
ulcers  are  false  pterygia,  and  should  be  sharply  distinguished  from  the  true  ones.  The 
ulcer  at  the  head  of  a  real  pterygium  is  purely  imaginary,  he  declares.  Ihe  true  ptery- 
gium always  results  from  a  pinguecula,  for  the  latter  has  an  unfavorable  influence  on  the 
nourishment  of  the  adjacent  cornea,  a  localized  corneal  inflammation  is  the  result,  and 
the  {Mnguecula  is  thereby  encouraged  to  grow  over  onto  the  cornea. 

The  prognosis  depends  altogether  upon  whether  or  not  an 
advance  of  the  pterygium  toward  the  corneal  center  is  to  be  ex- 
pected.    This  cannot  be  determined  by  inspection  alone.     It  may 

'  I  cannot  confirm  this  statement.  I  have  just  treated  a  patient  who  had  a  distinct 
pterygium  on  the  outer  side  of  the  cornea  and  nothing  on  the  inner  side. 


XEROSIS    EPITHELIALIS. 


21 


be  assumed,  however,  that  a  bulbous  head  protruding  above  the 
corneal  surface,  or  an  ulcer  at  the  edge  of  this  head,  or  small 
corneal  opacities  just  in  front  of  the  head,  all  indicate  a  progress- 
ing pterygium,  while  a  flat,  stringy  head  indicates  a  cessation  of  the 
grovvlh.  If  there  is  any  doubt,  it  is  best  to  use  the  strabometer 
[Fig.  J/,  /.  go)  from  time  to  time  to  measure  the  distance  of  the 
head  from  the  edge  of  the  cornea. 

Treatment  is  not  necessary  for  a  stationary  pter>'gium.  Any 
hv-peremia  can  be  treated  with 
zinc  solution,  or,  as  Zehender 
advises,  with  calomel  powder. 
The  progressive  pterygium 
should  be  removed  by  incision 
and  subsequent  approximation 
of  the  conjunctival  edges.  The 
neck  of  the  pterygium  is  seized 
with  fixation  forceps  {Fig.  j8), 
held  perpendicular  to  the  eye- 
ball ;  this  makes  it  possible  to 
loosen  the  head  from  the  cornea 
with  a  lance-shaped  knife  {Fig. 
7p)  introduced  on  the  flat. 
When  this  is  accomplished, 
two  converging  incisions  into 
the  body  are  made  with  scis- 
sors, and  the  part  thus  pre- 
pared is  dissected  away  from 
the  tissue  beneath  it  by  short 
cuts  with  the  scissors.  The 
lozenge-shaped  wound  is  now 
partly  closed  by  a  conjunctival 

suture,  which  must  be  j  to  j  mtn.  distant  from  the  sclero-comeal 
margin,  so  as  to  prevent  the  epithelial  covering  of  the  corneal 
wound  from  being  part  of  the  process  of  repair  in  the  conjunctiva. 

[e)  Xerosis  epithelialis. — The  conjunctiva  lying  exposed  beneath  the  palpebral 
fissure  appears  dn.-,  lusterless,  spotted,  and  uneven,  as  if  a  white  foam  had  dried  upon  it. 
It  has  a  fatty  structure,  as  is  shown  by  the  fact  that  fluids,  the  tears,  for  example,  flow 
over  it  without  wetting  it.  If  this  diseased  conjunctiva  is  scraped  and  the  crumby  sub- 
stance thus  obtained  examined  microscopically,  it  is  found  to  consist  of  fatty  degenerated 
epithelial  scales,  covered  with  numberless  bacilli,  "  xerosis  bacilli."  This  change  in  the 
conjunctival  epithelium  may  involve  the  cornea  as  well  and  produce  similar  deposits  on 


Fig.  78.— Fixation  For-    Fig.  79.— L.A»c».saAPS» 
CEPS  WITH  Catch  at  Kkifx. 

a  AKD  Tekth  at  6. 


214  DISEASES    OF   THE    CONJUNCTIVA. 

it,  which  may  lead  to  the  development  of  a  corneal  scar.  The  patient  visits  the  physician 
for  other  complaints  that  have  only  an  indirect  connection  with  xerosis.  Night  blindness 
(hemeralopia)  is  the  first  of  these.  The  common  ground  for  the  development  of  hemera- 
lopia  and  xerosis  is  a  state  of  impMiverished  nutrition. 

Treatment  must  be  directed  to  such  improvement  of  nutrition  as  each  case  may  de- 
mand. Locally,  warm  compresses  and  a  bandage  have  been  recommended,  but  the  usual 
involvement  of  both  eyes  makes  this  latter  inapplicable.  Besides  this,  considering  the 
bacilli  present,  even  though  they  are  only  harmless  parasites,  some  disinfectant  like  sub- 
limate vaselin  [o.ooj  :  lo.o)  or  iodoform  vaselin  (/  .•  lo)  is  made  appropriate. 

4.  INJURIES  AND  THEIR  CONSEQUENCES. 

[a)  Foreign  bodies  in  the  conjunctival  sac  are  of  very  frequent 
occurrence.  Lashes,  gnats,  seeds,  grains  of  sand,  bits  of  coal, 
splinters  of  wood  or  straw  or  iron,  wings  of  insects,  fragments  of 
glass,  and  other  debris  may  find  their  way  into  the  eye.  Whether 
or  not  the  foreign  body  works  itself  out,  depends  upon  its  size  and 
shape,  whether  round,  sharp,  uneven,  or  pointed.  There  is  always 
a  sensation  of  a  foreign  body,  with  pain  and  lacrimation  due  to 
reflex  irritation  of  the  lacrimal  gland.  In  many  cases  the  tears 
wash  the  particle  into  the  tear  sac,  whence  it  is  easily  disposed  of. 
In  other  cases  the  eye  itself  is  not  capable  of  getting  rid  of  the  little 
stranger.  It  is  driven  hither  and  thither  by  the  movements  of  the 
eye  and  lids  till  it  finally  finds  secure  lodgment  somewhere.  The 
favorite  locations  for  foreign  bodies  are  : — 

(i)  The  inner  surface  of  the  upper  lid,  2  to  j  mm.  from  the  pos- 
terior margins. 

(2)  The  shallow  border  between  cornea  and  sclera. 

(3)  The  upper  fornix. 

Anything  remaining  in  the  first  location  must  scratch  the  cornea 
at  every  movement  of  the  eye  and  therefore  cause  great  distress. 
To  remove  it  the  lid  should  be  everted  and  the  foreign  body  dis- 
lodged by  the  finger,  or  if  it  is  too  firmly  embedded,  by  a  needle  or 
a  chisel  spud  {Fig.  go,  p.  2^6). 

Foreign  bodies  are  often  removed  by  the  laity.  Locomotive  engineers  are  said  to  have 
a  trick  of  shoving  the  lower  lid  beneath  the  upper,  thus  wiping  away  any  foreign  body. 
Another  practice  of  the  laity  is  the  use  of  a  so-called  "  crab's  eye,"  which  is  a  small  lens- 
shaped  limestone,  convex  on  one  side  and  flat  on  the  other,  with  a  dimple  on  the  flat  side. 
These  stones  are  found  in  the  crab's  stomach.  They  are  placed  in  the  conjunctival  sac 
so  that  minute  foreign  bodies,  like  coal-dust  or  grains  of  sand,  are  caught  in  the  dimple. 
It  sometimes  happens  that  neither  the  foreign  body  nor  the  messenger  sent  after  it  comes 
out  again. 

Foreign  bodies  lodging  in  the  second  location  may  remain  with 
no  special  symptoms.     An  inflammatory  focus  is  produced  around 


WOUNDS HEMORRHAGE,  215 

them  so  that  they  may  at  times  be  mistaken  for  phlyctenules.  The 
third  location  is  chosen  by  larger  guests,  like  wisps  of  straw  or 
crab's  eyes.  They  may  remain  there  for  months  without  causing 
noticeable  trouble,  or  without  the  patient's  being  aware  of  their 
presence.  The  conjunctiva  itself,  however,  does  not  act  so  indiffer- 
ently;  it  hypertrophies  and  forms  a  wall  of  bleeding  granulations 
about  the  foreign  body.  In  that  case  the  foreign  body  is  not  easily 
removed  by  curette  or  sound  but  must  be  seized  with  forceps  and 
dragged  out.  The  granulations  do  not,  by  any  means,  disappear 
spontaneously,  but  should  be  cut  off  as  soon  as  the  foreign  body  is 
removed. 

(/;)  Wounds. — Wounds  of  the  conjunctiva  take  place  often  with- 
out injury  to  the  sclera,  as  when  boys  playing  "Indian"  shoot 
themselves.  External  hemorrhage  is  slight,  but  if  it  is  beneath  the 
mucous  membrane  it  seems  to  the  relatives  very  dangerous.  Small 
wounds  need  only  an  antiseptic  wash  (sublimate  solution  i :  jooo) 
and  closure  bandage.  A  larger  wound  may  require  a  conjunctival 
suture.  Clean  wounds  are  intentionally  made  by  the  surgeon  in 
strabismus  operations,  and  from  these  granulations  occasionally 
grow.  As  the  wound  closes,  its  edges  constrict  the  base  of  the 
little  tumor,  which  then  assumes  a  mushroom-like  shape.  If  left  to 
itself,  this  is  gradually  killed  by  the  contraction  of  the  scar.  The 
surgeon  need  not  wait  for  this  :  he  can  cut  off  the  base  with  scis- 
sors. ^ 

{c)  Hemorrhage  beneath  the  conjunctiva  is  often  the  result  of 
injuries  from  blows;  it  has,  of  itself,  no  significance,  and  disappears 
spontaneously  in  the  course  of  two  weeks  or  so.  The  question 
must  always  be  asked,  however,  whether  the  eye  has  been  other- 
wise injured  by  the  blow,  and  can  be  answered  by  testing  the  visual 
acuity  and  examining  the  eye  with  ophthalmoscope  and  focal 
illumination,  A  small  conjunctival  vessel  may  rupture  without 
external  evidence,  apoplexia  subconjunctivalis,  or  in  severe  fits  of 
coughing,  or  in  whooping  cough,  or  after  great  mental  excitement. 
That  one  can  get  "  bloody  eyes  "  from  anger  is  a  correct  observa- 
tion on  the  part  of  the  laity. 

In  old  people  these  spontaneous  hemorrhages  have  a  graver 
significance,  since  they  indicate  a  disease  of  the  vessels  (atheroma) 
which  may  cause  a  cerebral  hemorrhage  at  any  time.  One  should 
not  forget  to  look  for  sugar  in  the  urine  when  any  such  hemorrhage 
occurs. 


2l6  DISEASES    OF    THE    CONJUNCTIVA, 

{d)  Burns  are  apt  to  attack  the  cornea  and  even  the  sclera,  but 
to  a  certain  extent  the  cornea  is  protected  by  its  strong  epithelium 
and  the  sclera  by  the  conjunctiva  above  it.  For  this  reason  burns 
not  unusually  attack  only  the  ocular  conjunctiva.  They  may 
result  from  explosions  of  powder  and  dynamite,  from  the  spatter- 
ing of  molten  lead,  iron,  tar,  sealing  wax,  from  boiling  water,  from 
a  gas  flame  or  a  burning  cigar  or  matches.  Effects  quite  similar  to 
these  genuine  cauteries  are  produced  by  contact  with  concentrated 
acids,^  or  by  potash  or  lime  in  either  the  unslaked  or  slaked  form. 
This  most  commonly  gets  into  the  eye  as  mortar,  and  then  has  a  bad 
effect,  not  only  chemically,  but  also  mechanically  on  account  of  the 
sand  it  contains.  In  all  accidents  of  this  kind  there  is  very  decided 
pain,  and  where  the  conjunctiva  is  touched  a  scab  is  formed.  The 
conjunctiva  looks  yellowish  or  grayish-white,  and  its  sensitiveness 
is  reduced,  the  degree  of  this  anesthesia  being  an  indication  of  the 
depth  of  the  burn.  The  unaffected  tissue  is  quite  red  and  swollen. 
Healing  results  by  throwing  off  the  scab.  If  the  burn  was  so 
superficial  as  to  destroy  only  the  epithelium,  the  normal  condition 
is  quickly  restored ;  but  if  the  scar  penetrated  into  or  through  the 
tunica  propria,  the  result  is  a  cicatrix  that  may  lead  to  adhesion 
between  lid  and  eye  (symblepharon)  in  case  the  loss  of  tissue 
extends  to  the  fornix  or  involves  conjunctival  surfaces  opposed  to 
each  other. 

Very  slight  and  superficial  burns  are  not  e&sy  to  recognize.  As  a  rule,  only  a  red- 
dened spot  on  the  conjunctiva  is  seen,  although  this  is  not  diagnostic  ;  but  if  a  drop  of 
fluorescin  solution  ( /.  222)  is  placed  on  the  conjunctival  surface,  an  area  denuded  of 
epithelium  will  be  colored  yellowish-green. 

Treatment  begins  by  a  thorough  cleansing  of  the  eye,  since  the 
patient  is  usually  seen  too  late  for  the  effective  use  of  neutralizing 
acids  or  alkalies.  Water  should  not  be  used  if  bits  of  lime  are  in 
the  eye,  for  water  dissolves  the  lime  and  spreads  it  over  the  con- 
junctiva, producing  a  new  source  of  irritation.  Forceps  and  a  piece 
of  cotton  soaked  in  oil  is  the  best  method  to  use  in  these  cases. 
The  eye's  surroundings  should  then  be  carefully  washed  with  sub- 
limate solution  I  :  1000,  the  conjunctiva  with  i  :  jooo,  and  a 
bandage  applied.  To  diminish  the  severe  pain  a  few  drops  of  a  jT 
per  cent,  cocain  solution  may  be  dropped  into  the  eye  and  an  atro- 
pin-cocain  sa\we{Atrop.  sulf.  o.i ;   Cocain  inuriat.  0.2 ;    Vaselin  10.6) 

^  Burns  from  acids  are  caused  sometimes  with  criminal  intent. 


SYMBLEPHAKON.  21/ 

rubbed  into  it  before  the  bandage  is  applied.  The  scab  may  be 
encouraged  to  come  off  by  warm  compresses. 

(e)  Symblepharon. — We  distinguish  an  anterior  and  a  posterior 
symblepharon.  The  former  indicates  an  adhesion  of  the  lid  to  the 
eyeball,  forming  a  bridge  between  the  two,  but  not  extending  to 
the  fornix.  The  latter  refers  to  an  adhesion  reaching  to  the  fornix 
or  beginning  at  it.  These  adhesions  more  or  less  restrict  the  eye's 
movements,  or  they  may  so  anchor  the  lid  to  the  eye  in  front  of 
the  pupil  as  to  render  vision  impossible.  Every  means  must  be 
tried,  therefore,  to  prevent  such  an  adhesion.  This  can  generally 
be  done  if  the  two  opposed  burned  areas  do  not  extend  to  the 
fornix;  it  is  only  necessary  during  healing  to  separate  the  wound 
surfaces  daily  by  some  mechanical  means  and  to  prevent  their  sub- 
sequent sticking  together  by  applications  of  berated  or  iodoformed 
vaselin  (/  .•  /o).  If  the  burn  extends  to  the  fornix  nothing  can  be 
expected  from  such  means. 

If  an  anterior  symblepharon  already  established  is  to  be  treated, 
it  is  best  to  cut  the  adhesions  and  try  to  change  the  conditions  so 
that  wound  surface  does  not  come  into  contact  with  wound  surface 
but  with  mucous  membrane.  In  many  cases  this  can  be  done  by 
carrying  an  incision  through  the  conjunctiva  to  the  right  and  left 
of  the  wound,  and  by  transferring  the  loosened  mucous  membrane 
by  a  few  sutures  so  as  to  bring  it  over  one  wound  surface.  The 
e\'e  has  now  two  wound  surfaces,  but  the  lid  only  one,  and  this 
not  in  apposition  to  the  others ;  adhesion  is  therefore  impossible. 
In  a  small  anterior  symblepharon  a  simple  incision  through  the 
adhesion  with  subsequent  prevention  of  further  union  is  sufficient. 
If  the  symblepharon  is  posterior,  the  conjunctival  sac  can  be  re- 
paired and  a  freedom  of  movement  secured,  after  breaking  up  ad- 
hesions, only  by  transplantation  of  new  skin  or  mucous  membrane. 
The  healing  of  this  new  tissue  taken  from  the  patient  or  some  other 
person,  thanks  to  antisepsis,  will  usually  give  no  trouble;  but  the 
success  of  transplantation  may  be  nullified  by  subsequent  contrac- 
tion. It  will  be  a  matter  of  further  experience  before  it  is  decided 
which  tissue  is  best  suited  for  transplantation,  whether  cutis  (which 
becomes  changed  to  mucous  membrane),  or  mucous  membrane 
taken  from  the  mouth  or  the  vagina,  or  the  digestive  tract  of  the 
rabbit,  or  the  skin  of  the  frog. 


2l8  DISEASES   OF    THE    CONJUNCTIVA, 

5.  TUMORS. 

Lipoma  {Fatty  Tumor)  is  congenital.  It  remains  quiescent  for 
some  time,  but  may  later  on  begin  to  grow.  It  is  soft,  has  a  rough, 
lumpy  surface  and  a  yellow  color.  Strictly  speaking  it  is  not  a 
tumor  of  the  conjunctiva  but  of  the  underlying  connective  tissue, 
over  which  the  conjunctiva  passes  unchanged.  A  lipoma  is 
usually  found  on  the  upper  and  outer  quadrant. 

Polypi  are  pale-red,  pedunculated  little  tumors  of  0.5  to  /  cm. 
diameter,  usually  on  the  plica  semilunaris  or  the  lacrimal  caruncle. 
They  bleed  easily. 

Cysts  are  thin-walled  sacs,  somewhat  transparent,  filled  with  a 
watery  fluid,  and  having  the  form  and  size  of  half  a  pea  or  bean. 
They  are  usually  near  the  corneal  margin,  generally  congenital, 
but  may  develop  as  the  result  of  an  injury.  A  cyst  springs  from  a 
dilated  lymph  vessel.  In  rare  cases  conjunctival  cysts  spring  from 
the  bladder  of  the  cysticercus  cellulosae  {q.  v.).  Since  they  are 
not  in,  but  rather  below  the  conjunctiva,  this  form  of  cyst  appears 
less  thin-walled  and  transparent  than  others,  especially  as  the  con- 
junctiva may  become  inflamed  by  irritation  from  the  parasite.  In 
spite  of  this  the  neck  and  head  of  the  worm  may  glisten  as  a  whit- 
ish spot  within  the  cyst. 

Dermoid  tumor  is  yellowish,  and  has  the  size  and  shape  of  a 
split  pea,  lying  at  the  corneal  margin  in  the  lower  and  outer  quad- 
rant. It  can  with  equal  right  be  called  a  tumor  of  the  cornea. 
Dermoid  tumor  is  congenital,  and  may  remain  indefinitely  without 
increase  in  size.  If  it  begins  to  grow  it  is  not  a  pure  dermoid,  but 
a  mixed  form  of  dermoid  and  lipoma.  Histologically  it  is  found 
that  a  dermoid  consists  of  a  thick  layer  of  stratified  epidermis  cells 
beneath  which  are  connective  tissue,  fat  cells,  smooth  muscular 
fibers,  glands,  and  hairs,  all  being  tissues  of  the  external  skin.  Its 
origin  is  explained  by  supposing  a  piece  of  lid  to  have  become  at 
one  time  adherent  to  the  eyeball,  but  later  to  have  been  constricted 
at  its  lid  attachment  with  subsequent  growth  upon  the  eye  ;  hairs 
found  in  a  dermoid  would  therefore  be  dislodged  lashes.  It  may 
be  said  that  these  hairs  are  the  surest  signs  of  dermoid. 

Sarcoma  is  usually  found  at  the  limbus  of  the  conjunctiva,  and 
seldom  any  other  place,  although  Horner  mentions  a  case  discov- 
ered on  the  inner  surface  of  the  upper  lid.  The  tumor  is  peduncu- 
lated, vascular,  and  inclined  to  bleed ;  it  is  of  a  warty  surface  and 
grayish  brown  to  black  in  color  (Melanosarcoma).     This  latter  is 


CARCINOMA PEMPHIGUS AMYLOID.  2I9 

one  of  the  most  malignant  of  all  tumors,  but  the  sarcomata  lying 
superficially  are,  according  to  Schweigger's  experience,  relatively 
benignant — a  fact  to  be  considered  when  the  question  arises  whether 
or  not  the  globe  must  be  sacrificed. 

The  conjunctiva  bulbi  may  have  congenital  pigment  spots  which  do  not  noticeably 
alter  in  years,  and  must,  therefore,  be  considered  as  nevus  pigmentosus.  Nevertheless, 
one  must  always  consider  the  possibility  that  such  a  nevus  may  begin  to  grow,  and  in  the 
end  to  beccfme  a  melanosarcoma. 

Carcinoma  is  usually  found  at  the  sclero-corneal  margin.  Its 
growth  is  so  slow  and  painless  that  it  may  be  overlooked  in  diag- 
nosis. In  time  an  excrescence  develops,  whose  pedicle  passes 
gradually  into  the  conjunctiva — a  condition  not  found  in  a  phlyc- 
tenule or  an  inflammator)'-  focus.  With  a  lens  this  warty  character 
of  the  surface  may  be  recognized. 

Treatment. — Lipoma  is  to  be  shelled  out ;  polypus  to  be  re- 
moved by  excising  the  pedicle  down  to  healthy  tissue,  for  if  the 
pedicle  remains  it  will  grow  again.  A  cyst  is  to  be  opened  and  the 
walls  touched  with  nitrate  of  silver. 

Sarcomata  and  carcinomata,  being  malignant  tumors,  are  to  be 
radically  excised  down  to  what  appears  to  be  healthy  tissue,  and 
the  wound  must  be  cauterized  with  the  hot  iron.  If  the  disease 
has  involved  the  sclera,  enucleation  is  unavoidable. 

6.  EXTREMELY  RARE  DISEASES. 

(a)  Pemphigus  [Forma/iou  of  Vesicles). — It  has  been  occasionally  observed  that  a 
vesicular  eruption  at  the  mouth,  on  the  face,  or  on  the  extremities  has  been  accompanied 
by  a  similar  eruption  of  vesicles  (bullae)  on  the  conjunctiva.  These  vesicles  are  about 
the  size  of  a  pea  and  filled'  with  a  cloudy  fluid.  When  they  open  they  leave  a  shallow- 
ulcer,  which  heals  with  a  cicatricial  contraction  of  the  affected  conjunctiva.  Since  the 
process  repeats  itself  on  the  mucous  membrane  the  same  as  on  the  surface  of  the  body, 
there  may  be  in  the  course  of  years  a  considerable  distortion  of  the  conjunctival  sac,  or 
in  some  cases  an  adhesion  between  lids  and  eyeball  (/.  2ij),  or  a  xerosis  conjunctiva 
(/.  2i-j'\.  A  similar  condition  may  develop  very  gradually  without  pempiiigus  vesicles. 
In  Graefe's  clinic  five  such  cases  were  observed  and  reported  as  "  essential  contraction 
of  the  conjunctiva." 

Treatment  can  accomplish  little.  The  internal  use  of  arsenic  seems  powerless. 
Schmidt-Rimpler,  in  one  case  reported  by  him,  found  local  applications  of  boric  acid  com- 
presses and  the  styptic  use  of  tannin  and  nitrate  of  silver  solution  of  some  service. 

Amyloid  occurs  in  young  persons  who  may  be  quite  healthy  in  other  respects.  The 
patient's  attention  is  first  called  to  it  by  a  droop  of  one  or  both  upper  lids.  As  the  disease 
involves  a  greater  area  of  the  conjunctiva,  new  symptoms  appear,  such  as  lack  of  strength  in 
the  eye,  repeated  redness,  and  disturbances  produced  by  subconjunctival  hemorrhages  and 
by  the  protrusion  of  the  diseased  conjunctiva  into  the  palpebral  fissure.  The  eye  becomes 
useless  at  last,  because  the  patient  is  no  longer  able  to  open  the  swollen  and  distorted  lids. 


220  DISEASES    OF    THE    CORNEA. 

If  the  physician  everts  the  lids  he  sees  a  picture  greatly  resembling  that  of  the  second 
stage  of  trachoma  (/.  201).  In  both  cases  the  conjunctiva  is  hypertrophied  in  depth  and 
on  the  surface,  particularly  at  the  upper  fornix  ;  but  in  amyloid  this  hypertrophy  is 
greater  and  extends  over  the  entire  conjunctiva,  including  that  of  the  bulb.  Further 
differences  are  to  be  found  in  the  character  and  color  of  the  surface.  In  amyloid  the 
surface  is  smooth,  the  protruding  folds  of  the  fornix  being  the  only  irregularities.  In 
trachoma,  on  the  other  hand,  the  surface  is  roughened,  in  places  at  least,  by  the  inider- 
lying  follicles.  Amyloid  is  pale  yellow,  waxy,  and  transparent,  trachoma  a  dirty  reddish- 
yellow.  In  amyloid,  even  of  ten  years'  standing,  the  cornea  is  unaffected  ;  in  trachoma 
the  cornea  is  almost  always  attacked.  The  cause  is  unknown,  and  even  the  sages  have 
not  decided  what  the  histological  structure  of  the  changed  conjunctiva  really  is.  So 
much  is  certain,  however,  that  a  piece  of  tissue  cut  from  a  conjunctiva  with  amyloid  de- 
generation yields  on  pressure  a  jelly-like  substance  which  stains  violet  with  iodin  and 
sulfurous  acid,  thus  giving  the  distinct  color  reaction  for  amylum  or  amyloid.  The  de- 
tection of  this  color  reaction  on  an  excised  bit  of  tissue  should  never  be  neglected  in  the 
differential  diagnosis  between  amyloid  and  trachoma.  Treatment  consists  in  excision  of 
the  most  prominent  folds  with  expression  and  curetting  of  the  amyloid  substance.  If 
healing  does  not  result,  a  decided  improvement  is  at  least  obtained.  Cures  have,  how- 
ever, been  reported. 

Hyaline  degeneration  is  a  condition  scarcely  to  be  distinguished  clinically  from  the 
above.  The  difference  consists  chiefly  in  absence  of  the  amyloid  reaction.  Many 
authors  consider  hyaline  degeneration  a  distinct  disease  ;  others,  as  Raehlmann,  merely 
a  forerunner  of  amyloid. 


DISEASES  OF  THE  CORNEA. 

Preliminary  Remarks. — The  contents  of  the  eyeball  is  enclosed  in  a  threefold  en- 
velope. The  tunica  externa  is  the  outer  coat ;  its  smaller  anterior  segment,  the  cornea, 
is  as  transparent  as  glass,  its  larger  and  posterior  segment, //^^  sclera, '\s  like  porcelain  and 
untransparent.  Both  segments  have  a  thickness  of  /  mm.  or  more,  and  are  of  decided 
density,  so  that  they  are  a  protective  mantle  for  the  delicate  inner  membranes.  The 
cornea  is  the  segment  of  a  sphere  of  ^.j-  to  8  mm.  radius,  the  sclera  is  the  segment  of  a 
sphere  of  12  mm.  radius.  The  cornea  is  fitted  into  the  sclera  like  a  watch  crystal  into 
its  case.  It  consists  of  five  layers  {^Fig.  4, p.  2^).  The  middle  layer  is  by  far  the  thick- 
est, being  about  95  percent,  of  the  whole  ;  it  is  called  the  substantia  propria  comeic  and 
cornea  sclerw.  It  consists  of  extraordinarily  fine  connective-tissue  fibrils.  These  fibers 
are  matted  together  into  bundles,  which  are  placed  in  layers  over  each  other ;  between 
these  lamellae  are  a  series  of  inter-communicating  spaces  called  lacunae ;  these  lacunas 
with  their  canals  form  the  lymph  system  of  the  cornea.  .Since  the  cornea  must  be  trans- 
parent, it  is  obvious  that  blood  cannot  circulate  in  these  lymph  spaces,  because  the  nu- 
trient fluid  formed  there  must  also  be  quite  transparent.  This  fluid  consists  of  a  clear 
lymph  with  a  moderate  number  of  ameboid  cells,  white  blood  corpuscles.  Besides 
movable  contents  there  are  found  in  the  corneal  lacunas  immovable  cells  called  the 
fixed  corneal  corpuscles.  The  anterior  structureless  membrane  is  called  the  lamina 
elastica  anterior  or  Reichert's  or  Bowman's  membrane  {Fig.  S2,p.  224).  Morphologic- 
ally this  belongs  to  the  substantia  propria.  Above  Bowman's  membrane  lies  the  corneal 
epithelium  disposed  in  eight  or  nine  layers  of  cells  {Fig.  86,  p.  241).  The  innermost 
layers  consist  of  cylindrical  cells  arranged  with  the  long  axis  perpendicular  to  the  cornea  ; 


INFLAMMATIONS  OF  THE  CORNEA.  221 

the  three  or  four  superficial  layers  are  pavement  cells  with  their  long  axes  parallel  to  the 
surface  of  the  cornea  ;  the  middle  layers  are  cuboidal.  The  corneal  epithelium  forms 
the  coujutictiva  cornetF.  The  posterior  surface  of  the  substantia  propria  is  covered  by 
the  glass-like  and  structureless  lamina  elastica  posterior  or  Descemefs  vietnhrane  {Fig.  82). 
In  spite  of  its  thickness  of  only  0.006  mm. ,  this  membrane  is  very  strong.  Its  poste- 
rior surface  is  covered  with  a  single  deposit  of  flat  endothelial  cells,  the  fifth  and  last 
layer  of  the  cornea.  The  fourth  and  fifth  layers  together  are  called  choroidea  cornea 
because  they  belong  morphologically  to  the  middle  tunic  of  the  eye. 

Although  the  cornea  has  not  and  cannot  have  blood-vessels  of  its  own,  it  is  by  no 
means  cut  off  from  the  nutrition  supplied  by  the  blood  current.  At  the  corneal  margin 
superficially  there  lies  a  network  of  blood-vessels  {Fig.  So),  ready  at  any  moment  to  push 
on  into  the  cornea  new- formed  vessels.  There  are  also  vessels  at  the  scleral  margin 
deeper  down,  from  which  this  vascularization  may  proceed. 

Since  the  cornea  is  in  immediate  contact  with  the  outer  world  and  thereby  exposed  to 
all  manner  of  injury,  it  possesses  a  special  protective  mechanism.  This  consists  of  an 
extraordinarily  rich  supply  of  nerves,  and  obviously  if  the  transparency  of  the  eye  is  to 
be  maintained  these  nerves  must  be  of  the  non-medullated  variety.  The  branches  of  the 
nerves  extend  to  the  uppermost  layer  of  the  corneal  epithelium.  If  the  cornea  is  irri- 
tated  by  dust  or   wind,  if  it   is  too   dry,  or  if  in   any  way  it   resents    interference,  then 


Fig.  80. — Vascular  Network  at  the  Corneal  Margin.     {After  IValdeyer.") 
Red,  arteries.     Blue,  veins. 

through  these  nervous  fibrils  an  impulse  is  sent  for  the  lids  to  close  and  protect  it  and  for 
the  tears  to  wash  it  clean. 

The  sclera  is  similar  but  less  regular  in  structure  ;  a  lamina  elastica  anterior  with  its 
epithelium  is  unnecessary,  since  the  surface  of  the  sclera  is  not  exposed,  but  is  protected 
partly  by  the  conjunctiva,  partly  by  Tenon's  capsule.  Decemets  membrane  with  epi- 
thelium is  unnecessary  because  the  inner  surface  of  the  sclera  does  not  line  the  space 
filled  with  fluid  ;  both  inner  and  outer  surfaces,  therefore,  are  covered  only  with  a  large- 
celled  endothelium,  in  order  to  facilitate  the  movement  against  Tenon's  capsule  on  the 
one  side  and  the  middle  tunic  on  the  other. 


I.  INFLAMMATIONS  OF  THE  CORNEA. 

I.  General  Consideraiio?is. — Inflammations  of  the  cornea  form  not 
only  the  majority  of  corneal  diseases,  but  a  goodly  proportion  of 
all  eye  diseases  as  well.  They  demand  particular  attention,  because 
they  very  often  leave  behind  opacities  of  the  cornea  and  the  incur- 
able disturbances  of  vision  connected  with  them.    What  determines 


222  DISEASES    OF   THE    CORNEA. 

a  corneal  inflammation  ?  The  four  usual  signs  of  inflammation — 
heat,  swelling,  redness,  and  pain — are  not  here  at  all!  Since  the 
cornea  is  non-vascular,  in  a  recent  inflammation  there  can  be  no 
redness.  Since  it  is  unelastic,  there  can  be  no  swelling.  Pain,  to 
be  sure,  is  present,  but  it  is  by  no  means  exceptional  to  see  an 
inflammation  in  the  deeper  layers  of  the  cornea  run  its  course  with 
no  pain  whatever.  Heat  depends  upon  blood  congestion,  and  can, 
therefore,  play  no  part  in  a  non-vascular  tissue.  Hence  it  is  plain 
that  we  must  search  for  another  sign  which  will  be  present  in  all 
corneal  inflammations :  this  sign  is  cloudiness.^  The  cause  of  this 
cloudiness  or  opacity  is  to  be  found  in  a  collection  of  leukocytes 
that  have  passed  into  the  cornea  from  the  adjacent  blood-vessels, 
or  have  sprung  upon  the  fixed  corneal  cells  by  karyokinesis. 

Opacity  causes  an  impairment  of  vision,  often  the  only  complaint 
of  the  patient,  although  in  most  cases  he  complains  of  pain,  photo- 
phobia, and  lacrimation.  The  pain  is  easily  distinguished  from 
that  of  conjunctivitis  by  the  fact  that  it  is  not  limited  to  the  diseased 
area,  but  radiates  to  the  forehead  and  upper  jaw,  the  so-called 
ciliary  pain,  because  the  nerves  of  the  cornea  arise  from  the  nervi 
ciliares.  Objective  examination  shows  swelling  and  redness  of  the 
lids  and  congestion  of  the  conjunctival  vessels;  a  quite  important 
sign  is  the  injection  of  the  deep  sub-conjunctival  vessels  that  arise 
from  the  ciliary  arteries  {see  p.  182),  "  pericorneal  injection  "  or 
"ciliary  injection;  "  in  the  cornea  itself  there  may  be  any  kind  of 
opacity,  and  the  iris  may  be  congested  or  inflamed. 

2.  INFLAMMATIONS  WITH  THE  FORMATION  OF  ULCER. 
{d)  Ulcus  Corneae  {Corneal  Ulcer). — If  there  are  signs  of  corneal 
inflammation  and  if  a  loss  of  substance  can  be  found,  we  can  speak 
of  an  ulcer.  Demonstration  of  this  loss  of  substance  can,  in  doubt- 
ful cases,  be  simplified  by  the  use  of  fluorescin,  introduced  by 
Straub,  A  drop  of  a  solution  {Fluorescin  o.i ;  Natr.  carb.  0.2  ;  aq. 
dest.  sterilis.j.6)  is  placed  in  the  conjunctival  sac  and  at  once  washed 
off  with  warm  sterilized  water  or  sublimate  solution  i :  ^000.  Any 
spot  on  the  cornea  which  has  lost  its  epithelium  will  be  colored  a 
vivid  green.^     In  a  crying  and  struggling  child  the  glance  of  a 

^  There  are  corneal  opacities  of  a  non-inflammatory  nature  ;  these  will  be  discussed  later. 

*  Diseased  epithelium  will  also  be  colored  green,  as,  for  example,  the  epithelium  cover- 
ing an  eczematous  pustule  ;  but  such  a  spot  is  only  dull  green,  while  a  spot  actually 
denuded  of  its  epithelium  appears  to  be  saturated  with  a  vivid  green. 


ULCUS    CORNE.-E.  •        223 

moment  will  show  what  the  condition  is  better  than  the  most  care- 
ful examination  without  fluorescin.  If  an  ulcer  is  proved  to  be 
present,  this  is  by  no  means  all  that  must  be  done ;  we  must  deter- 
mine whether  the  ulcer  is  beginning,  or  spreading,  or  healing  ;  we 
must  further  find  out  whether  the  ulcer  arose  (/)  from  external 
infection,  {2)  from  extension  of  some  conjunctival  disease  to  the 
cornea,  (j)  from  some  nervous  disease,  or  (^)  from  some  systemic 
disturbance.  It  will  then  be  possible  to  give  to  the  ulcer  its  own 
personality,  which  completes  the  description  of  the  disease. 
Although  it  is  often  easy  to  recognize  what  stage  the  ulcer  has 
reached,  it  is  quite  as  often  difficult  or  even  impossible  to  decide 
what  was  its  origin.  We  must,  therefore,  be  content  with  the  name 
corneal  ulcer,  and  reserve  the  right  to  complete  the  designation  at 
any  succeeding  examination. 

Ulcers  originate  in  two  ways.     Either  a  wound  causes  a  loss  of 


Fig.  81. —  Beginning  Corneal  Ulcer.     (After  Samisck.) 

The  upper  layers  of  epithelium  are  partly  lacking.     At  Bowman's  membrane   a  layer  of  pus-cells   is 

seen.     In  the  substantia  propria  are  numerous  small  groups  of  pus-cells. 

epithelium,  so  that  the  door  is  opened  for  the  entrance  of  bacteria, 
which  effect  a  suppurative  infiltration  of  the  neighboring  tissue  ;  or 
this  infiltration  is  the  earlier  process  which  leads  to  a  later  destruc- 
tion of  the  superficial  corneal  layer  with  its  epithelium  and  the 
subsequent  ulcer  {Fig.  81).  In  the  first  stage  the  ulcer  has  the  fol- 
lowing appearance :  the  base,  where  tissue  has  been  lost,  looks 
grayish  or  yellowish,  uneven  and  rough;  the  edge  is  irregular, 
jagged,  and  torn  {Fig.  82);  the  neighborhood  of  the  ulcer  is  usually 
clouded,  but  in  a  few  cases  it  may  be  clear  and  unaffected.  As 
long  as  the  ulcer  progresses,  new  areas  of  the  cornea  melt  into  it ; 
the  loss  of  tissue  becomes  greater;  pain,  lacrimation,  photophobia, 
and  dimness  of  vision  become  more  pronounced,  or  are  at  least 
unimproved.  At  last  the  turning-point  comes  and  healing  begins. 
The  base  of  the  ulcer  is  a  little  less  clouded,  for  the  detritus  cover- 
ing it  is  disappearing;  the  ulcer  looks  clear  and  smooth,  for 
epithelial  cells  are  spreading  across  it  from  edge  to  edge  {Fig.  8j). 


224 


DISEASES    OF   THE    CORNEA. 


For  the  same  reason  the  edge  of  the  ulcer  is  rounded  off,  and  is 
less  sharp  than  before  the  adjacent  cloudiness  clears  up,  or  is  at 
least  restricted  to  the  immediate  neighborhood  of  the  ulcer. 
Finally,  new-formed  blood-vessels  are  seen  {Fig.  8j)  either  because 
they  have  developed  up  to  the  ulcer,  or  because  the  marginal  vas- 


■fyMe^fum- 


Jfejndnme         =^ 


Fir.  82. — Progressing  Ulckr.     (After  Samisch.) 
The  neighborhood  of  the  ulcer  is  infiltrated  with  pus-cells. 


cular  network  was  so  close  to  the  ulcer  that  new  vessels  could 
easily  branch  out  from  it.  At  the  same  time  a  decided  improve- 
ment in  the  patient's  symptoms  sets  in.  As  soon  as  the  base  of 
the  ulcer  is  again  able  to  reflect  light,  we  may  assume  that  it  is 
covered  with  epithelium  and  that  the  essential  requirement  of  heal- 
ing has  been  complied  with.     To  be  sure,  the  lost  tissue  is  not  yet 


Fig.  83. — Healing  Ulcer.    (After  Samisch.') 
The  infiltration  has  disappeared.     The  base  of  the  ulcer  is  covered  with  young  epithelial  cells. 


completely  replaced;  this  occurs  gradually  by  the  formation  of 
new  connective  tissue  below  the  epithelial  covering,  and  sometimes 
in  elderly  persons  is  never  completed.  Until  the  tissue  is  fully  re- 
stored there  remains  a  corneal  "  facet."  The  new-formed  connective 
tissue  resembles  corneal  tissue,  but  is  not  so  completely  transparent. 


ULCUS    CORNEiE. 


•^-D 


As  the  facet  grows  shallower  the  cloudiness  becomes  more  opaque. 
The  younger  the  patient  the  sooner  can  one  expect  a  gradual  clear- 
ing up  of  this  scar. 

The  favorable  course  here  described  is  the  usual  one  in  cases 
properly  treated  ;  but  we  must  learn  to  recognize  the  exceptions 
that  turn  out  very  unfavorably.  If  the  ulcer  has  eaten  through 
the  entire  thickness  of  the  substantia  propria  the  internal  pressure 
of  the  eye  rests  alone  on  Descemet's  membrane.  This  becomes  so 
stretched  that  it  bulges  into  the  ulcer,  filling  it  completely.  Since 
the  base  of  the  ulcer  now  lies  on  this  surface,  is  transparent,  and 
reflects  light,  the  inexperienced  observer  maybe  misled  into  believ- 
ing that  such  a  corneal  hernia,  keratocele,  is  an  unexpectedly  rapid 
healing.  The  experienced  observer,  however,  will  be  attracted  by 
the  undiminished  irritation  in  the  eye  to  its  actual  condition,  which 
he  can  then  corroborate  by  means  of  lens  and  focal  illumination. 
If  the  ulcer  advances  further  the  result  is  a  perforation  ;  the  aqueous 
flows  away  between  the  lids,  the  iris  is  either  stretched  across  the 
aperture  or  is  dragged  completely  through  it — prolapsus  iridis. 
The  effect  of  the  perforation  is  favorable  to  the  ulcer;  the  reduction 
of  the  eye's  tension  encourages  the  circulation  in  the  cornea,  and 
the  round  cells  attracted  hither  can  now  succeed  in  effecting  the 
demarcation  and  destruction  of  all  unhealthy  tissue,  and  a  cleans- 
ing of  the  ulcer.  Healing  results  by  the  prolapsed  iris'  changing 
into  granulation  tissue  arid  uniting  to  the  adjacent  corneal  scar. 
The  iris  remains  permanently  adherent  to  the  white  corneal  scar,  a 
condition  called  leucoma  adherens.  If  the  perforation  is  very  small 
the  iris  may  again  retract,  leaving  the  patient  with  only  a  simple 
corneal  scar.  If  the  ulcer  was  exactly  at  the  center  of  the  cornea, 
the  anterior  lens  surface,  instead  of  the  iris,  falls  into  the  opening 
when  perforation  occurs.  The  result  is  an  opacity  of  the  lens 
capsule  at  the  anterior  pole — anterior  central  capsular  cataract. 
A  perforation  at  the  center  of  the  cornea  may  result  in  another 
evil,  for  if  the  iris  does  not  reach  to  the  point  of  perforation,  but  is 
yet  near  enough  to  act  as  a  wedge  and  thereby  to  prevent  the  lens 
from  closing  the  aperture,  the  perforation  remains  open,  and  the 
result  is  a  corneal  fistula  through  which  the  aqueous  continuously 
trickles.  The  eyeball  is  thus  softened  and  ill  nourished,  and 
finally  atrophies,  unless  nature  or  art  effects  a  speedy  closure  of  the 
fistula. 

15 


226  DISEASES  OF  THE   CORNEA. 

There  must  be  mentioned,  finally,  the  worst  cases  of  corneal 
ulcer,  in  which  a  large  pa.rt  of  the  cornea,  or  all  of  it,  within  a  re- 
markably short  time  is  eaten  away  by  the  pus,  and  where  the  iris 
prolapses  to  a  great  extent  or  totally,  and  even  the  lens  or  pxart  of 
the  vitreous  may  be  let  out.  Such  a  case  may  lead  to  an  atrophy 
of  the  eyeball — phthisis  bulbi.  In  other  cases  a  cure  may  be  effected 
if  the  prolapsed  iris  becomes  covered  with  cicatricial  tissue.  A 
cicatrix  with  adherent  iris  will  often  bulge  forward  on  account  of 
the  internal  pressure  of  the  eye,  forming  a  berry-like  tumor,  which 
will  be  discussed  under  staphyloma  cornecB  {p.  2jj). 

The  prognosis  depends  upon  the  location,  size,  and  nature  of  the 
ulcer,  as  well  as  upon  the  resistance  which  the  corneal  tissue  is 
capable  of  opposing.  In  general,  only  this  much  can  be  said  :  that 
a  yellow  color  of  the  base  and  edge  of  the  ulcer  indicates  pus  infil- 
tration and  further  destruction  of  tissue,  but  that  areas  of  the 
cornea  provided  with  blood-vessels,  "  vascularized,"  are  protected 
from  destruction  ;  the  mere  proximity  of  vessels  assures  some  pro- 
tection ;  therefore  the  corneal  zone  bordering  on  the  marginal 
network  of  blood-vessels  remains  undestroyed,  even  if  the  entire 
cornea  suppurates.  It  may  be  given  as  a  good  rule  that  advanced 
age  and  a  poorly  nourished  condition  of  the  patient  tend  to  make 
the  prognosis  bad,  because  both  circumstances  reduce  the  cornea's 
power  of  resistance  and  reaction.  The  prognosis  is  also  essentially 
modified  by  treatment. 

Treatment  attempts  to  accomplish  three  objects  : — 

(1)  The  eye,  like  any  other  diseased  organ,  is  to  be  made  to  rest, 
and  is  to  be  protected  from  new  injury. 

(2)  The  ulcer  is  to  be  disinfected. 

(3)  The  nutrition  of  the  corneal  tissue  and  the  natural  healing 
dependent  upon  it  is  to  be  as  much  as  possible  encouraged. 

To  accomplish  the  first  object,  atropin,  the  pressure  bandage,  and 
rest  are  at  our  disposal.  Atropin  subdues  the  pain  and  overcomes  the 
inflammation.  We  can  often  see  how  the  ciliary  injection  noticea- 
bly subsides  within  half  an  hour  after  atropin  has  been  dropped  into 
the  eye.  Atropin  is  also  indicated  on  account  of  the  iris.  Every 
active  inflammation  affects  the  adjacent  parts  in  sympathy,  and 
therefore  iris  hyperemia  or  even  an  iris  inflammation  is  a  not  unu- 
sual result  in  corneal  ulcer.  Atropin  stops  the  play  of  the  pupil 
and  prevents  the  formation  of  {xwterior  synechia. 


ULCUS    CORNE.E.  22/ 

Atropin  should  not  be  applied  if  corneal  perforation  threatens,  or  if  perforation  is 
already  present.  In  such  a  case  one  must  apply  the  exactly  opposite  remedy  {Eserin 
sulf.  0.02J  :   Aq.  salicylat.  j.o  ;  ^  om  drop  hvice  a  day^. 

Eserin  effects  a  powerful  contraction  of  the  pupil,  increasing,  of  course,  the  irritation 
of  the  iris  but  reducing  the  internal  tension  of  the  eye,  and  therefore  reducing  the  pres- 
sure against  the  cornea.  Moreover,  it  must  be  remembered  that  in  a  tense  and  dis- 
tended iris  the  danger  of  a  prolapse  is  much  less,  and  consequently  we  are  warranted  in 
hoping  that  in  spite  of  a  perforation  we  may  effect  a  cure  without  anterior  synechia,  that 
is,  adhesion  between  iris  and  cornea. 

The  pressure  bandage  prevents  movements  of  the  lid,  and  pro- 
tects the  eye  from  light.  Rest  in  bed  is  indispensable  in  severer 
cases,  and  acts  favorably  by  keeping  the  whole  body  quiet,  and  par- 
ticularly by  lessening  the  demands  upon  the  healthy  eye. 

For  the  second  object,  disinfection,  we  have  a  number  of  remedies 
at  hand.  In  the  mildest  cases,  it  is  enough  to  wash  the  lids 
thoroughly  with  sublimate  solution,  and  to  douche  the  conjunctival 
sac  with  sublimate  /  .•  jooo.  The  ulcer  may  be  dusted  with  finely 
powdered  iodoform.'  A  bandage  will  prevent  secondary  inflam- 
mation from  dirty  fingers,  dust,  etc.,  and  it  is  best  to  use  for  this 
purpose  antiseptic  material,  such  as  cotton  prepared  with  sublimate 
solution  (/  .•  looo) ;  or  if  eczema  results  we  take  iodoform  gauze. 
If  the  ulcer  progresses  in  spite  of  this  treatment,  stronger  means  of 
disinfection  should  be  used.  The  strongest,  and  at  present  most 
popular,  is  the  galvano-cautery,  with  which  every  part  of  the  cornea 
that  seems  to  be  in  danger  is  cauterized.  Since  many  ulcers  pro- 
gress only  from  their  edges,  in  these  cases  it  is  not  necessarj'  to 
cauterize  the  whole  ulcer  but  only  the  advancing  portion.  The 
result  of  the  cautery  is  a  brilliant  one  in  case  every  infected  area  is 
actually  destroyed,  and,  when  only  this  infected  portion  is  destroyed, 
the  scar  is  no  greater  than  it  would  have  been  without  such  a  radical 
procedure. 

I  seldom  use  the  cautery,  if  I  find  that  a  milder  method  does  quite  as  good  service. 
By  this,  I  mean  the  scraping  of  the  ulcer  with  a  sharp  spoon  or  a  chisel.  If  the  ulcer  is 
colored  green  with  fluorescin  before  the  operation,  the  green  color  serves  as  a  guide  to 
limit  the  curetting.  After  fluorescin,  cocain  is  applied,  and  after  the  operation  every- 
thing is  washed  away  with  sublimate  solution,* and  an  antiseptic  bandage  is  put  on. 


^  Eserin  sulfate,  di^olved  in  distilled  water,  soon  becomes  red.  If  salicylic  acid  is 
added  to  the  water  the  solution  remains  colorless. 

^  Stilling  proposed  to  use  the  diffusible  anilin  dyes  as  disinfectants,  and  he  introduced 
methyl  violet  into  practice  under  the  name  of  "  Pyoktanin,' '  pus  destroyer.  P\oktanin  has 
been  tried  by  many  surgeons  in  different  eye  diseases,  particularly  in  corneal  ulcers.  It  is  as 
yet  undecided  what  effect  it  has,  but  it  is  probably  not  so  favorable  as  Stilling  at  first  hoped. 


228  DISEASES    OF    THE    CORNEA. 

In  the  tliird  group  of  remedies  moist  heat  plays  an  important 
part.  It  may  be  assumed  that  its  effect  is  to  arouse  a  reactive  in- 
flammation and  to  encourage  the  sloughing  of  the  already  necrotic 
tissue ;  moreover,  it  encourages  the  development  of  protecting 
blood-vessels,  and  at  the  same  time  lessens  the  pain.  It  is  there- 
fore used  in  all  cases  where  the  pain  is  great,  and  where  the  disease 
pursues  the  subacute  course.  It  is  particularly  useful  in  non-irri- 
tating ulcers  and  infiltrations,  where  this,  reactive  inflammation  is 
ordinarily  lacking.  Moist  heat  can  be  applied  as  a  warm  compress 
of  chamomile  tea,  or  three  per  cent,  boric  acid  solution,  or  as  an 
ordinary  moist  warm  compress.  If  the  last  is  applied  it  may  be 
prevented  from  drying  by  covering  the  bandage  with  a  layer  of  oil 
silk. 

Puncture  of  the  base  of  the  ulcer  has  the  same  effect  as  moist 
heat.  When  the  aqueous  escapes,  the  cornea  has  less  pressure 
upon  it ;  the  circulation  of  fluids  in  the  lymphatics  is  encouraged, 
and  the  ulcer  is  better  drained.  The  experience  that  perforated 
ulcers  heal  quickly  of  themselves  first  suggested  the  resort  to  this 
measure.  In  the  worst  cases  it  is  not  sufficient  to  puncture  the 
base  of  the  ulcer  with  a  needle,  it  must  rather  be  incised  with  a 
Graefe's  cataract  knife  {Fig.  126)  from  healthy  tissue  to  healthy 
tissue,  and  the  wound  must  be  opened  for  several  days  follow- 
ing with  an  aseptic  probe.  In  short,  the  ulcer  must  be  treated 
as  an  ordinary  abscess.     This  is  called  ScBinisch's  operation. 

This  is  an  operation  I  seldom  resort  to ;  although  I  have  just  had  a  case  in  which  the 
ulcer,  in  spite  of  radical  curetting,  made  such  rapid  progress  and  became  so  large,  that  I 
could  not  even  think  of  cauterizing  every  part  of  the  area  involved. 

If  the  iris  prolapses  we  may  try  to  drag  it  out  of  the  wound  by 
eserin.  If  this  is  not  successful,  we  must  await  the  healing  of  the 
ulcer,  and  then  attempt  to  abscise  the  prolapse  (/.  2^8)  or  to 
burn  it  off  with  the  cautery. 

A  corneal  fistula  is  treated  in  the  same  way  with  eserin  and  pres- 
sure bandage.  If  this  method  is  unavailing  we  must  try  to  destroy 
the  epithelial  covering  of  the  fistula  by  means  of  the  cautery. 

When  the  base  of  the  ulcer  reflects  light,  and  ciliary  injection  and 
the  other  signs  of  irritation  have  disappeared,  the  treatment  with 
stimulants  should  be  begun.  Daily  massage  with  yellow  mercurial 
ointment  encourages  the  absorption  of  the  round  cells  in  the  neigh- 
borhood of  the  former  ulcer  and  the  obliteration  of  the  new-formed 
blood-vessels.      Both  results  are  apparent — to  the   physician   by 


ULCUS    CORNER. 


229 


clearing  up  of  the  opacity,  and  to  the  patient  by  improvement  in 
visual  acuity  (if  the  opacity  lay  near  the  center  of  the  cornea). 

(a)  Ulcus  serpens,  Hypopyon  Keratitis,  usually  attacks  poor 
people  in  advanced  age.  The  disease  most  commonly  results  from 
an  injury  to  the  eye, — for  example,  when  a  twig  has  scratched  that 
part  of  the  cornea  exposed  within  the  palpebral  fissure,  etc.,  or 
when  some  splinter  of  wood  or  any  kernel  of  grain  flies  into  the 
eye  and  makes  a  small  wound.  Even  the  scratch  from  an  eyelash 
may  be  enough  to  cause  it.  Such  little  injuries  of  themselves  would, 
as  a  rule,  have  no  serious  consequences,  but  if  germs  have  entered 
the  little  wound,  although  it  may  have  closed  a  short  time  after  it 
was  made,  the  result  is  a  corneal  ulcer  having  a  remarkable  inclina- 
tion to  spread  superficially  and  profoundly — ulcus  serpens.  Germs 
may  be  introduced  by  the  object  causing  the  injury;  this  is  partic- 
ularly common  in  the  case  of  injuries  made  while  working  with 
farming  tools.  In  perhaps  one-third  of  the  cases  they  get  into  the 
wound  from  the  pus  of  a  blennorrheic  tear-sac  (/.  IJ2).  In  still 
other  cases,  germs  may  enter  from  the  discharges  of  an  inflamed 
conjunctiva,  of  a  lid,  or  from  the  nose  or  mouth.  Infection  from 
the  nose  or  mouth  may  be  accomplished  by  dirty  handkerchiefs 
and  fingers,  since  many  people  have  a  habit  of  using  saliva  to  wash 
out  the  eye  when  it  itches.  Finally,  it  must  be  remembered  that 
any  corneal  ulcer  may  be  changed  to  an  ulcus  serpens  by  secondary 
infection. 

Undoubtedly  there  are  many  kinds  of  gerrns  able  to  produce  an 
ulcus  serpens.  Investigations  made  up  till  now  have  shown  the 
presence  of  one  or  more  of  the  following :  staphylococcus  pyogenes 
albus  and  aureus,  gonococcus,  streptococcus,  anthrax,  typhoid  or 
diphtheria  bacilli,  and  aspergillus  glaucus,  leptothrix  buccalis. 

Symptoms  of  the  patient — lacrimation,  photophobia,  and  ciliary 
pains — are  extraordinarily  various  and  bear  no  relation  to  the  sever- 
ity of  the  disease.  The  objective  phenomena  of  irritation,  "  peri- 
corneal injection,"  are  quite  as  various.  The  visual  disturbance,  on 
the  other  hand,  is  always  noticeable,  since  the  ulcer  lies  within  the 
territory  of  the  palpebral  fissure,  and,  indeed,  in  or  close  to  the 
center  of  the  cornea. 

The  edge  of  the  ulcer  forms  a  yellowish-white  curved  line,  or  a 
group  of  smaller  curves  clustered  together ;  a  radiating  bundle  of 
delicate  gray  spokes  passes  from  them  into  the  still  transparent 
corneal  tissue.     The  ends  of  the  spokes  are  connected  by  delicate 


2JO  mSEASES  OF  THE  CORXEA. 

bundles  rnimuig  neaHy  parallel  to  die  edge  of  tibe  nicer.  At  the 
posterior  wall  erf*  the  nicer  tfaeie  is  Ibnod,  in  cases  vhere  the  inflam- 
mation is  severe,  a  giaqrish  dood  diat  extends  even  into  the  anterMn- 
chamber.  The  aqueous  is  tfacrelbre  rendered  opaque  by  pus  ceils. 
If  tbis  ccJIection  of  pus  odls  reacbes  a  certain  d^rce.  die  setdii^ 
of  die  ceils  win  produce  on  tbe  floor  of  tfae  anterior  cbamber  a 
ydlonrisb-looldng  mass,  which  is  bcM-dered  above  by  a  horizontal 
line  and  below  by  tbe  ei^e  of  tfae  cornea,  and  is  tfaerefbre  in  tbe 
shape  of  an  arc ;  this  is  called  J^pofjfim}  Accorvfing  to  Sxmisch, 
hypopyon  occurs  in  70  per  cenL  of  serpiginous  ulcers. 

The  iris  also  is  involved  in  tl^  inflammation  and  becomes  adhe- 
rent to  the  anterior  sur^KS  of  the  lens — sjmedda  posUriar?  Even 
irido-cyditis  and  suppuration  of  the  entire  eye  taacf  be  produced, 
but  this  danger  usually  threatens  in  diose  cases  where  the  first  de- 
vdopments  of  tfae  diitcase  occurred  in  tfae  deqper  layers  of  tfae 
cornea.  A  loss  of  substance  tfaen — an  ulcer — is  not  at  first  present, 
tfae  disease  beginning  as  a  corneal  abscess^  as  a  round,  ydlowish 
disk  in  the  center  of  the  cornea  moderately  sw<41en  at  the  edge. 
The  sur&ce  of  this  lesion  is  flat  and  somewhat  depressed.  Until 
the  abscess  breaks  and  forms  an  ulcer,  it,  iA  course,  increases  in 
size,  both  in  surface  and  depth,  which  gives  to  diis  particular  form 
its  dangerous  character.  It  may  be  produced  in  an  intact  cornea 
by  germs  that  have  migrated  into  the  cornea,  from  the  blood  cur- 
rent. This  may  happen,  although  not  often,  after  severe  infectious 
diseases,  as  tyj^ioid  fever,  scarlet  (ewer,  and  particulariy  after  small- 
pox. It  is  i^ener  tfae  case  tfaat  germs  are  admitted  tfarough  a 
minute  wound  of  the  e]Mthdium,  which  has  already  healed  when 
tfae  abscess  b^;ins  to  show  itsdC 

The  pn^nons  is  un^voraUeu  In  die  best  of  orcumstances  tfae 
disease  may  heal  with  an  opaque  corneal  scar,  often  with  anterior 
and  posterior  synechiac.  The  treatment  of  this  form  of  conical 
ulcer  occasionally  necessitates  Saexnisch's  operation  at  the  base  of 
tbe  ulcer. 


{^  Vvcm  Roscas. — !■  apte  of  die  ■■Jlaiij  oT  die  ■■■«,  wicms  lodoB  1m»  UiOe 
m  common  mA  item  aaptmt.  Uloa  aapemi  »  am  wemt  iKw  mi-  IcaJwg  to  jB|y rtw 
^utamt6om«t  Aeconwa,  to  kjpapiiMi,  aad  evea  to  indo-c^dtti;  tdoBaodeaa,  oadK 
odwr  kaad,  is  a  dboMC  dfaese,  wfcick  m  &e  oemck  of  ! 


*  Sirr  fcypapfw  »  «  ■earfy  coartt  ocfumcc  a  ideas  seqwat,  Kowr  aaaed  tbe 
WB  tfilid». 
of  dK  im  widi  Ae  eoaook  »  aBed  ipudkm  amUri^. 


ULCERATIVE    CORNEAL    INFLAMMATION    FROM    CONJUNCTIVA.     23 1 

missions,  scales  off  the  most  superficial  layers  of  the  cornea  without  perforating  the 
cornea  itself,  or  even  without  penetrating  into  its  deeper  layers.  Ulcus  rodens  begins  at 
the  margin  of  the  cornea,  and  passes  step  by  step,  with  decided  irritation,  jmin,  photo- 
phobia, lacrimation,  and  ciliary  injection,  across  the  middle  of  the  cornea  and  ends  at  the 
opposite  margin.  The  base  of  the  ulcer  is  seldom  deeper  than  the  surface  of  the  cornea. 
It  is  rather  opaque  and  abundantly  supplied  with  vessels  springing  from  the  marginsil  net- 
work. The  edge  of  the  ulcer  is  whitish,  abrupt,  and  somewhat  undermined;  minute 
white  points  in  the  neighboring  but  still  healthy  cornea  are  outposts  and  signs  of  a  further 
advance  of  the  disease.  Nothing  is  yet  known  of  any  causative  germ.  As  treatment, 
the  obliteration  of  the  advancing  edge  of  the  ulcer  with  the  cautery  may  be  advised ;  the 
application  of  nitrate  of  silver  has  done  good  service ;  atropin  and  a  bandage  .are  always 
to  be  used. 

[U)  Ulcerative  Corneal  Inflammation  Arising  from  the  Con- 
junctiva. 

(a)  Keratitis  eczematosa  {Lymphatica,  Scrofidosa,  PJilyctcnu- 
losd)  attacks  children,  chiefly  those  who  suffer  from  eczema  of  the 
skin,  of  the  lids,  and  particularly 
of  the  conjunctiva;  to  avoid  a 
repetition  the  student  is  referred 
to  p.  2oy.  Keratitis  eczematosa 
does,  however,  occur  in  adults 
and  in  healthy  children  with  in- 
tact conjunctiva.  The  disease  is 
extraordinarily  various,   since   in 

,  I,  Fig.  84. — Phlyctenular  Keratitis.  {After 

one  case  there  are  small  eczema  luumoff.) 

„    •    1 /„l,i    .„*.„„. .l^„      C\"^    P  .\  .   :.■.  This  consists  of  .1  collection  of  piis  cells  be- 

VeSlCleS  (phlyctenules,  /^/^<^.i./);   in  ^^.^en   the    epithelium   and   the   snbstanii.^ 

.It  .1  propria.     The  b.tnd  p.-ts&inij;  obliquely  to  it 

another,    large   eczema    pustules,         Ts  a  corneal  nerve. 

since  ulcers  may  spring  up  from 

this  eczema,  producing  on  the  same  cornea  lesions  of  different  size 

and  character  next  to  each  other ;  and  since,  finally,  an  eczematous 

ulcer  may  lose  its  own  peculiarities  by  any  infection  added  to  it. 

The  study  will   be  essentially  simplified  if  we  differentiate  with 

Horner — 

(i)  Eczema  passing  from  the  conjunctiva. 

(2)  Eczema  originating  in  the  cornea, 
(l)  A  single  phlyctenule  lies  at  the  limbus  of  the  conjunctiva 
but  extending  a  bit  onto  the  cornea.  At  this  spot  there  will  be  an 
opacity  of  the  cornea,  which  disappears  if  the  progress  is  favorable  ; 
if  it  is  unfavorable  it  changes  to  a  funnel-like  ulcer  or  is  inclined  to 
sink,  step  by  step,  and  to  cause  a  perforation  with  all  its  conse- 
quences. Or,  the  marginal  phlyctenule  may  form  the  first  stage  of 
a  bundle  of  vessels  of  a  corneal  inflammation — keratitis  fascicul arts. 


232  DISEASES   OF   THE    CORNEA. 

While  this  phlyctenule  is  healing  on  the  conjunctiva  it  is  advancing 
on  the  middle  of  the  cornea  and  drags  the  sheaf  of  new-formed 
vessels  behind  it.  The  appearance  of  such  a  vascular  condition  is 
unusually  characteristic,  and  is  easily  distinguished  from  the  or- 
dinary vascular  ulcer  arising  at  the  edge  of  the  cornea — first,  by 
the  parallelism  of  the  vessels ;  second,  by  the  opacity  of  the  vas- 
cular area  of  the  cornea ;  and  third,  by  the  sharp  contrast  of  the 
opaque  cornea  with  the  healthy  cornea  marked  by  two  parallel 
lines.  The  apex  of  the  bundle  of  vessels  is  a  yellowish  crescent 
with  its  concavity  turned  toward  the  vessels ;  this  is  a  small  ulcer 
with  an  infiltrated  base  and  a  raised  edge.  The  vessels  may  dis- 
appear, but  the  opacity  never  does ;  it  remains  during  life. 

The  picture  becomes  somewhat  different  if  a  larger  number  of 
conjunctival  phlyctenules  attack  the  cornea;  the  mildest  involve- 
ment of  the  cornea  is  called  phlyctenular  marginal  pannus — keratitis 
superficialis  vasculosa.  It  is  characterized  by  a  slight  opacity  and 
vascularization  of  a  corneal  area  bordering  directly  on  a  conjunc- 
tival limbus  having  these  phlyctenules.  It  is  to  a  certain  extent 
only  an  inflammatory  product  which  has  involved  the  cornea.  A 
severer  form  is  the  eczematous  circular  ulcer;  this  is  characterized 
by  small  infiltrations,  each  corresponding  to  conjunctival  phlyc- 
tenules springing  up  along  the  corneal  margin,  changed  into  ulcers 
and  soon  after  run  together.  Circular  ulcers  under  some  circum- 
stances may  threaten  even  the  center  of  the  cornea,  since  a  sup- 
purative infiltration  and  necrosis  may  involve  a  part  of  the  cornea 
extending  to  its  very  center. 

(2)  Idiopathic  eczema  of  the  cornea  is  somewhat  simpler  in  its 
manifestations.  Horner  distinguishes  three  forms,  the  differences 
consisting  in  a  greater  or  less  depth  and  extent  of  the  commencing 
infiltrate,  from  which  smaller  or  larger  ulcers  develop,  which  in  the 
worst  cases  may  lead  to  hypopion  and  iritis.  The  infiltrate  is 
seen  as  a  somewhat  raised  grayish  point  about  the  size  of  a  pin- 
head,  sometimes  on  a  clear  cornea,  at  other  times  on  a  cornea 
moderately  opaque. 

Every  infiltrate  need  not  change  to  an  ulcer.  Even  the  large  ones,  yellow  in  color 
and  of  considerable  depth,  may  be  dissolved  under  proper  treatment  without  producing 
an  ulcer ;  in  spite  of  which,  however,  there  is  left,  as  a  rule,  an  incurable  opacity.  This 
keratitis  eczematosa  resulting  from  an  infiltrate  is  really  a  very  serious  disease,  needing 
from  four  to  six  weeks  for  its  cure ;  but  the  final  result  is  better  than  might  be  expected 
from  the  threatening  appearance  it  has  in  its  full  development. 


ULCERATIVE  CORNEAL  INFLAMMATION.  233 

Treatment  consists  of  atropin,  douches  of  sublimate  solution 
•7  .•  jooo,  bandage,  and  warm  compresses  when  proper.  Good 
nutrition  is  particularly  important  in  this  form. 

All  forms  of  eczema  of  the  cornea  produce  in  the  majority  of 
cases,  besides  the  ordinary  symptoms  of  irritation,  an  extraordinary 
degree  of  photophobia,  which  may  increase  to  an  actual  spasm  of 
the  lid  {p.  137).  The  epithelium  of  the  cornea  is  remarkably  rich 
in  nerves,  and  for  that  reason  superficial  corneal  inflammations 
occasion  severe  reflex  symptoms.  The  use  of  the  eyes  demands 
movements  of  the  lids,  and  movements  of  the  lids  irritate  the  sur- 
face of  the  cornea  already  diseased ;  it  is  no  wonder,  then,  that 
children  instinctively  creep  into  the  darkest  corner  of  the  room, 
burying  their  faces  in  cushions,  or  by  squeezing  their  fists  into  their 
eyes  seek  to  prevent  the  physician  from  getting  a  look  at  them. 

The  prognosis  is  doubtful.  If  left  to  itself  the  disease  that  at 
the  beginning  was  merely  superficial  or  sub-epithelial,  is  cured  only 
after  months  of  distress,  leaving  behind  it  numerous  opacities  of 
greater  or  less  density,  which  disturb  the  visual  acuity  the  whole 
life  long.  If  the  treatment  is  a  proper  one,  the  prognosis  is,  on 
the  other  hand,  essentially  better.  The  general  treatment  has  been 
discussed  on  p.  2og.  The  local  treatment  differs  with  the  stage  of 
the  disease.  If  the  case  is  a  recent  one  of  corneal  phlyctenule  or 
simple  infiltrate  a  soothing  treatment  is  in  place.  In  such  a  case 
I  use  inunctions  of  atropinized  vaselin  {o.i  :  10.6)  and  a  bandage. 
If  an  ulcer  has  already  formed,  the  treatment  for  corneal  ulcer  is 
the  proper  one, — that  is,  douches,  atropin,  iodoform,  bandage,  and,  if 
the  improvement  is  not  rapid,  curetting,  which  removes  granula- 
tions occupying  a  rather  deep  space  undermining  the  edge  of  the 
ulcer.  This  space  is  particularly  developed  at  the  apex  of  the 
vascular  tissue.  If  the  severest  symptoms  of  irritation  have 
passed,  or  if  the  ulcer  has  begun  to  heal,  it  should  be  treated  by 
stimulants,  calomel  powder,  or  yellow  ointment.  This  is  also 
applicable  to  eczematous  pannus. 

If  there  is  a  doubt  whether  it  is  an  open  ulcer  or  a  new  infiltrate, 
the  fluorescin  test  should  be  applied  ;  if  the  diseased  area  is  colored 
green  it  is  not  yet  the  proper  time  for  a  stimulating  treatment.  An 
exception  to  this  is  offered  in  the  case  of  suppuration  from  the 
conjunctiva,  which,  if  present,  may  be  treated  with  two  per  cent, 
nitrate  of  silver  solution,  even  if  a  recent  ulcer  is  present ;  after 
this,  atropinized  vaselin  and  a  bandage  should  be  applied. 


234  DISEASES    OF    THE    CORNEA. 

Photophobia  of  children  has  been  traditionally  overcome  by  a  few  seconds'  dousing  of 
the  face  in  cold  water.  It  is  easV  to  see  that  children  for  the  moment  forget  their  fear  of 
light  in  their  fear  of  choking  to  death,  and  that  they  therefore  open  their  tightly  closed 
lids  at  the  dread  of  it ;  but  such  a  result  does  not  last  long  and  is  certainly  purchased  at 
the  expense  of  mental  agony  to  the  child.  It  is  just  as  ea.sy  to  obtain  the  effect  with 
milder  means,  cold  water,  for  example,  or  in  any  case  by  a  cold  douche  ;  moreover,  the 
sensitiveness  of  the  cornea  can  be  reduced  by  atropin,  or  even  better  by  cocain,  both  of 
which  may  be  applied  in  the  form  of  ointments  {Atropin  siilf.  o.i ;  Vaselin  lo.o;  or  Cocain 
mur.  0.2 ;  Vaselin  lo.o)  ;  the  mere  covering  of  the  cornea  with  a  layer  of  vaselin  has  a 
good  effect  in  moderating  irritation.  In  case  the  eczema  has  already  changed  to  an  ulcer 
a  bandage  is  unconditionally  demanded.  As  soon  as  the  cornea  begins  to  improve,  the 
photophobia,  as  a  rule,  diminishes. 

(^)  Catarrhal  Ulcer  is  a  disease  of  elderly  people  suffering 
from  chronic  conjunctivitis.  It  looks  something  like  a  furrow  run- 
ning parallel  to  the  edge  of  the  cornea,  appearing  most  usually 
above,  that  is,  in  that  part  of  the  cornea  covered  by  the  lid.  Often 
there  are  several  ulcers  along  the  edge  of  the  cornea,  one  after  the 
other.  The  first  stage  of  catarrhal  ulcer  is  usually  an  infiltrate  or  a 
group  of  pinhead-like  infiltrates,  which  gradually  coalesce  into  an 
ulcerous  furrow.  The  prognosis  is  favorable.  The  treatment  is 
that,  in  general,  of  corneal  ulcer  ;  if  the  secretion  from  the  conjunc- 
tiva is  very  abundant  this  must  be  at  the  outset  overcome  by  appli- 
cation of  two  per  cent,  nitrate  of  silver  solution. 

(>•)  Corneal  Ulcer  in  Trachom.\. — Ulcers  are  not  regular  occurrences  in  tra- 
choma ;  they  are  not  dangerous  to  the  eye  if  they  are  at  the  edge  or  within  the  area  of  a 
corneal  pannus,  since  the  vascularized  cornea  is  to  a  certain  extent  protected  against 
necrosis.  If,  on  the  other  hand,  in  acute  trachoma  (/.  igg)  there  is  a  loss  of  corneal 
epithelium,  the  result  may  be  a  dangerous  ulcer  produced  by  infection  from  the  conjunc- 
tival secretion  so  rich  in  bacteria.  Ulcers  of  a  pannused  cornea  need  no  particular  treat- 
ment ;  they  heal  of  themselves  if  the  conjunctiva  is  treated  properly.  Ulcers  in  acute 
trachoma  should  be  treated  according  to  the  same  principles  as  in  blennorrhea. 

{S)  Corneal  Ulcer  in  Blennorrhea. — This  ulcer  begins  with 
a  smgill,  scarcely  perceptible  loss  of  epithelium  at  the  apex  of  the 
cornea.  Twenty-four  hours  afterward  there  is  a  round  or  elliptical 
infiltrate  present,  which  is  decidedly  greater  than  was  the  loss  of 
epithelium.  The  infiltrated  portion  melts  rapidly  away.  The  depth 
of  the  ulcer  is  easily  underestimated,  since  its  base  only,  not  the 
edges  and  surroundings,  are  clouded.  Horner's  is  the  best  method 
of  recognizing  this  funnel-like  extension — very  oblique  (tangential) 
inspection,  of  course  with  the  aid  of  focal  illumination.  A  cure 
may  be  effected  by  the  reproduction  of  the  epithelium  to  replace 
what  was  already  lost;  this  new  form  of  tissue,  in  the  course   of 


INFLAMMATION    FROM    DISEASE    OF   THE    NERVES.  235 

years,  becomes  more  and  more  like  true  corneal  tissue,  and  more 
and  more  nearly  transparent.  A  cure  may  again  result  by  the 
development  of  blood-vessels,  which  are  spread  to  the  ulcer  from 
the  lower  edge  of  the  cornea.  Or,  finally,  a  keratocele  is  produced, 
followed  by  a  perforation,  before  healing  is  accomplished. 

Another  form  begins  like  a  catarrhal  ulcer  but  does  not  seem  to 
have  any  inclination  to  heal ;  it  rather  creeps  along  the  edge  of  the 
cornea,  so  that  a  circular  ulcer  is  produced,  which,  as  Saemisch 
says,  to  a  certain  extent  undermines  the  cornea  and  destroys  it. 

Treatment  consists  in  the  speediest  cure  of  the  conjunctiva  (/. 
79/).  The  ulcer  itself  is  to  be  protected  as  far  as  possible  from  in- 
fection with  the  conjunctival  secretion,  by  means  of  inunctions  of 
borated,  sublimated,  or  iodoformized  vaselin.  The  bandage  is  in- 
admissible, since  it  would  retard  the  removal  of  the  pus  that  ought 
to  be  removed  as  rapidly  as  possible.  If  perforation  threatens,  eserin 
should  be  used.  Even  after  perforation  eserin  acts  favorably,  and 
often  drags  the  prolapsed  iris  back  into  the  anterior  chamber,  or 
at  least  away  from  the  surface  of  the  cornea. 

(e)  Corneal  Ulcer  in  Diphtheria  begins  with  a  delicate  cloudiness,  the  corneal 
area  appearing  as  if  it  had  been  just  breathed  on ;  then  follows  loss  of  epithelium,  infil- 
tration of  pus,  and  necrosis.  According  to  Horner  the  color  of  a  diphtheritic  ulcer  is 
yellow  or  even  a  yellowish-brown,  darker,  therefore,  than  a  blennorrheic  ulcer;  another 
distinction  lies  in  the  rapid  course  of  the  diphtheritic  process,  twenty-four  hours  being 
often  sufficient  to  cover  the  progress  from  loss  of  the  epithelium  to  perforation.  If  the 
diphtheritic  ulcer  begins  with  the  conjunctival  disease,  say  on  the  first  or  second  day,  the 
eye  is  surely  lost,  for  the  cornea  must  have  been  accidentally  supplied  with  blood-vessels 
from  some  ulcerous  disease — an  eczema,  for  example.  If  the  ulcer,  on  the  other  hand, 
does  not  develop  until  the  end  of  the  first  week,  we  may  hope  to  retain  at  least  a  part  of 
the  cornea.  Ulcers  arising  later  are,  of  course,  still  less  dangerous.  The  treatment  is 
that  of  a  blennorrheic  ulcer. 

(1?)  Keratitis  Punctata  Superficialis  (Fuchs). — During  an  acute  conjunctival 
catarrh  in  young  persons  there  may  develop  a  number  of  small,  gray,  elevated  points  in  the 
superficial  areas  of  the  cornea.  These  points  are  in  groups  and  rows,  or  are  spread  over  the 
entire  cornea.  The  disease  is  more  often  bilateral  than  unilateral ;  the  irritation  produced 
by  them  soon  disappears  but  the  dots  remain  for  months.  I  have  seen  two  cases  that 
fitted  to  Fuchs'  description,  except  that  in  them  the  disease  of  the  conjunctiva  was  deeper 
and  more  rebellious.  The  appearance  of  these  gray  dots  in  the  cornea  was  but  an  act  in 
the  drama  of  an  extremely  rebellious  conjunctival  catarrh,  defying  the  usual  treatment. 

(c)  Inflammation  Resulting  from  Disease  of  the  Nerves. 

(a)  Herpes  Zoster  Ophthalmicus  Corne^-e. — Herpes  describes 
a  group  of  small  vesicles  filled  with  a  watery  fluid.  Herpes  of  the 
skin,  as  a  phenomenon  of  a  disease  of  the  first  branch  of  the  tri- 
geminus, has  been  mentioned  on/,  i^j.    This  herpes  zoster  ophthal- 


236  DISEASES    OF   THE    CORNEA. 

micus  at  times  passes  onto  the  cornea.  The  vesicles  are  very- 
transient,  and  are  usually  broken  before  the  physician  catches  sight 
of  the  patient,  the  physician  finding  only  a  group  of  small  corneal 
ulcers.  However,  the  disease  is  easily  recognized  by  the  herpes, 
or  the  fresh  scars  of  it  on  the  forehead,  and  by  the  patient's 
description  of  the  pain  which  accompanied  it.  This  disease  has, 
besides,  two  particular  diagnostic  signs :  anesthesia  of  the  cornea 
and  softness  of  the  eyeball. 

The  sensation  of  the  cornea  may  be  proved  by  touching  it  with 
a  cone  of  paper.  Normally,  the  lightest  touch  will  excite  an  im- 
mediate closure  of  the  lids.  If  the  sensation  is  reduced,  however, 
the  lid  does  not  even  wink.  Anesthesia  may  be  of  itself  the  cause 
of  a  disease — keratitis  neiiroparalytica  [p.  2j8), 

In  a  dissertation  by  J.  Wanglar,  he  reports  six  cases  of  herpes  zoster  in  which  the 
vesicle  and  ulcers  did  not  appear,  the  only  local  condition  being  small  opacities  lying  just 
below  the  epithelium.     Within  the  area  of  these  opacities  the  cornea  was  anesthetic. 

(/5)  Herpes  Febrilis  (Horner). — Vesicles  of  o._^  to  i.o  mm.  in 
diameter  develop  on  one  cornea  with  profuse  lacrimation  ;  gener- 
ally a  group  of  these  forms  a  connecting  line 
somewhat  fork-shaped.     These  vesicles  exist  for 
an  extremely  short  time  ;  they  break  so  soon  that 
when  a  physician  makes  an  examination  he  sees 
only  the  result  of  the  vesicles,  irregularly  bordered 
FiG.85.-HERPET.cUL-     ulcers  {Fig.  8^)  having  a  great  similarity  to  the 
^auer.)  "'^"     Superficial  injuries  (epithelial  scabs).     The  naked 

eye  can  scarcely  detect  any  opacity  of  the  cornea, 
but  with  a  lens  a  delicate  gray  cloudiness  near  the  ulcer  may  be  seen. 
The  ulcer  itself  is  the  only  anesthetic  portion  ;  the  remaining  cornea 
being  sensitive.  Healing  takes  place  without  the  growth  of  blood- 
vessels, although  it  takes  much  longer  than  in  equally  extensive 
loss  of  substance  from  other  causes.  If  the  ulcer  becomes  infected 
it  loses  its  characteristic  appearance,  and  may  assume  all  the  pecu- 
liarities of  an  ulcus  serpens.  The  latest  investigations  of  Haab 
have  shown  that  a  new  crop  of  herpes  vesicles  may  spring  up, 
which  coalesce  with  the  old  ulcers  and  appear  to  be  a  continuance 
of  them.  The  peculiarly  branched  form  of  a  herpetic  ulcer  has 
attracted  to  itself  several  distinct  descriptions,  with  such  names  as 
keratitis  dendritica,  keratite  ulcereuse  en  sillons  etoiles,  keratitis 
ramiformis. 


INFLAMMATION    FROM    DISEASE    OF   THE    NERVES.  237 

It  should  not  be  forgotten  that  the  discoverers  of  these  forms  of  keratitis  have  energeti- 
cally opposed  the  reproach  that  they  have  described  cases  of  herpes  as  distinct  diseases ; 
for  example,  Enimert  distinguishes  keratitis  dendritica  from  herpes  in  the  following  way : 
"  Keratitis  dendritica  is  not  preceded  by  a  general  febrile  condition  ;  the  conjunctiva  of 
the  upper  lid  is  more  swollen  than  it  is  in  herpes.  In  exceptional  cases  keratitis  dendri- 
tica begins  as  a  sub-epithelial,  grayish  opacity,  forming  a  tree-like  figure  ;  the  epithelium 
about  it  is  puffed  up  and  of  a  grayish  color ;  after  this  epithelium  has  been  thrown  off  the 
grayish  furrow  is  seen  beneath  it,  which  forms  a  tree-like  ulcer." 

I  have  just  had  under  treatment  a  girl  whose  eye  became  inflamed  after  an  acute 
fever  of  two  days.  I  was  thus  able  to  show  the  case  to  a  pupil  as  a  typical  herpes  in 
statu  nascendi,  that  is,  in  the  vascular  stage.  The  next  day  I  showed  the  case  to  a  young 
physician  from  Berne,  who  exclaimed  with  great  pleasure  :  "  That  is  a  case  of  keratitis 
dendritica!"  To  be  sure,  the  vesicles  had  disappeared,  although  ulcers  were  by  no 
means  present,  but  only  two  delicate,  superficial,  treelike  opacities,  which  branched  out 
from  two  dense,  round,  marginal  infiltrations  toward  the  center  of  the  cornea.  Thanks 
to  the  early  treatment,  there  was  no  formation  of  ulcer  at  all.  I  am  compelled  to  con- 
clude, therefore,  that  keratitis  dentritica  is  only  a  form  of  herpes  comese. 

Herpes  corneae  febrilis  is,  like  herpes  of  the  lips  and  of  the  nose, 
a  symptom  of  a  febrile  disease,  particularly  of  inflammation  of  the 
lungs  and  of  grippe  ;  but  a  collection  of  150  cases  made  by  Haab 
has  shown  that  in  about  half  the  number  a  general  febrile  condition 
could  not  be  demonstrated.  If  we  consider  that  herpes  belongs  to 
the  rare  diseases,  that  febrile  disturbances  are,  on  the  other  hand, 
of  daily  occurrence,  that  herpes  is  often  extraordinarily  pain- 
ful and  almost  always  confined  to  one  side,  and  that  this  herpes 
corneae  has  the  greatest  resemblance  to  the  demonstrably  neurotic 
herpes  zoster,  it  is  admissible,  for  the  present  at  least,  to  group  it 
among  the  neurotic  inflammations. 

The  course  is  a  slow  one,  lasting  for  weeks,  or  often  months ; 
only  the  mildest  cases  and  those  treated  from  the  very  beginning 
will  heal  without  a  scar.  The  scar  of  herpes  is  so  characteristic 
that  the  diagnosis  of  herpes  may  be  often  made  long  after  the  dis- 
ease has  been  cured.  The  surface  of  the  scar  remains  for  months 
uneven,  a  particularly  noticeable  sign  when  the  shallowness  of  a 
herpetic  ulcer  is  considered.  The  edge  of  the  scar  is  very  irregular, 
as  if  a  fork  of  lightning  had  passed  across  the  cornea.  Since  the 
scar  tissue  forms  only  a  very  thin  layer,  the  scar  itself  appears  of  a 
delicate  gray,  and  can  be  well  seen  only  with  focal  illumination ;  it 
is  generally  free  from  blood-vessels.  Since  herpetic  ulcers  show 
no  inclination  to  extend,  the  treatment  may  be  confined  to  the 
gentlest  measures,  with  atropin,  disinfection,  and  the  bandage. 

By  scraping  with  a  sharp  spoon  I  have  in  two  or  three  days  cured  ulcers  which  have 
defied  milder  measures  for  weeks  at  a  time.      I   therefore  resort  to  this  little  operation 


238  DISEASES    OF    THE    CORNEA. 

with  much  greater  freedom.  For  after-treatment  massage  with  yellow  ointment  is  to  be 
recommended.  This  should  not  be  begun  too  early,  however,  particularly  if  the  cornea 
is  still  uneven. 

Keratitis  Filamentosa  (Fadchen-Keratitis). — After  injuries  to  the  cornea,  after  herpes 
and  similar  ulcers,  there  may,  at  times,  be  seen  little  threads  hanging  from  the  area  which 
has  been  denuded  of  epithelium.  They  consist  of  metamorphosed  epithelial  cells 
twisted  together  into  a  thread.  Occasionally  such  threads  may  be  seen  on  an  otherwise 
healthy  cornea,  suggesting  the  diagnosis  of  a  special  disease. 

(y)  Ker.\titis  Neuroparalitica. — If  the  nervus  trigeminus  of  a  rabbit  be  severed 
within  the  cranial  cavity,  either  in  front  of  or  at  the  Gasserian  ganglion,  the  animal  utters 
a  cry,  the  pupil  of  the  affected  eye  contracts,  and  the  cornea  and  conjunctiva  become 
anesthetic.  On  the  following  day  the  center  of  the  cornea  is  cloudy,  the  cloudiness  in- 
creases, the  grayish-white  color  turns  to  yellow,  and  the  cornea  dies  in  a  suppurative 
condition.  This  process  is  called  keratitis  neuroparalitica.  \Vhat  is  the  explanation  of 
it  ?  An  immense  number  of  theories  gives  us  about  as  many  contradictory  answers.  One 
view  is  that  on  account  of  the  anesthesia  of  the  cornea  small  injuries  may  happen  to  it, 
which  are  changed  into  creeping  ulcers  by  the  entrance  of  germs.  This  explanation  is 
correct  but  by  no  means  complete,  since  injuries  to  the  cornea  in  a  rabbit  whose  nerve 
has  not  been  cut  do  not  show  the  least  inclination  to  change  into  ulcers.  Others  answer 
by  saying  that  the  cause  of  the  disease  is  a  drying  up  of  the  cornea,  since  section  of  the 
trigeminus  deprives  the  lacrimal  gland  of  its  functions  and  prevents  closure  of  the  lid. 
This  explanation,  also,  is  insufficient,  since  it  is  well  known  that  a  healthy  rabbit  does 
not  secrete  tears  unless  he  be  particularly  stimulated,  nor  does  he  wink  very  much.  A 
third  and  more  probable  explanation  is  given  by  Gaule,  who  observed  that  section  of  the 
trigeminus  produced  on  the  epithelium,  the  endothelium,  and  the  fixed  corneal  cells  changes 
that  could  be  demonstrated  by  the  microscope  (cellular  subdivision  on  the  one  hand, 
cellular  death  on  the  other).  These  changes  are  by  no  means  a  keratitis  neuroparalitica, 
nor  do  they  necessarily  produce  it,  but  the  power  of  resistance  in  the  cornea  is  so  much 
reduced  that  external  influences  such  as  dryness,  injuries,  and  germs  may  easily  accom- 
plish the  destruction  of  the  cornea.  How  the  section  of  the  nerve  or  ganglion  produces 
these  demonstrable  changes  in  the  corneal  cells  has  itself  not  yet  been  explained. 

Keratitis  neuroparalitica,  such  as  is  artificially  produced  on  an 
animal,  may  happen  to  man,  although  less  typical  and  less  pure. 
Pathological  changes  in  the  cranial  cavity,  hemorrhages,  new 
growths,  syphilitic  gummata,  and  the  like,  are  not  as  sharply  de- 
fined as  a  firm  puncture  or  section  by  the  hand  of  a  skilled  opera- 
tor. Cases  of  trigeminus  paralysis  in  man  are,  therefore,  not  so 
complete,  and  are,  moreover,  associated  with  paralysis  of  other 
nerves,  the  oculomotor,  the  abducens,  the  facialis,  for  example ; 
the  preceding  description  of  keratitis  in  a  rabbit  is  consequently 
applicable  to  that  in  man,  but  its  course  in  man  is  much  more 
chronic.  Moreover,  it  is  a  peculiar  fact  that  in  man  the  por- 
tion of  the  cornea  covered  by  the  upper  lid  will  often  remain 
uninjured. 

Prognosis  and  treatment  must  depend  upon  the  causative  disease 


ULCERS    FROM    GENERAL    DISEASES.  239 

within  the  cranium.     Of  course,  care  must  be  taken  that  the  cornea 
is  protected  from  dryness,  from  injury,  and  from  infection. 

((5)  Keratitis  Biixosa. — Vesicles  of  ^  to  j  mm.  diameter  spring  up  on  the  cornea 
in  the  center  or  the  lower  half,  less  often  on  the  upper  half,  accompanied  by  considerable 
pricking  pain.  They  are  moderately  filled  with  fluid,  hang  downward  like  a  bag,  and 
are  moved  hither  and  thither  by  the  edge  of  the  lid.  The  wall  of  the  vesicle  usually 
consists  of  nothing  but  corneal  epithelium.  After  a  few  days  the  vesicle  breaks,  its  con- 
tents is  discharged,  and  the  remnants  of  the  wall  are  worn  oflf  by  the  lids.  As  soon  as 
the  vesicle  breaks,  the  symptoms  of  irritation  subside.  In  a  few  days  the  epithelium  is 
reproduced,  and  the  moderate  opacity  of  the  cornea,  apparent  at  the  site  of  the  vesicle, 
gradually  clears.  This  would  end  the  matter  if  the  process  were  not  repeated,  after  a 
greater  or  lesser  interval  of  quiet ;   but  the  disease  may  extend  over  months  in  this  way. 

The  nature  of  the  disease  is  not  known  ;  the  best  presumption  is  that  some  disease  of 
the  corneal  nerves  is  at  the  bottom  of  it.  Its  recurrent  appearance  and  the  fact  that  in 
many  cases  there  is  decided  pain  in  the  territory  of  the  supraorbital  nerve,  accompanied 
by  a  moderate  swelling  on  the  forehead,  would  support  this  view. 

Keratitis  bullosa  may  attack  healthy  eyes  or  eyes  that  have  been  previously  irritated 
by  some  scratch.  It  is  most  commonly  observed  in  glaucoma  absolutum,  in  glaucoma 
secundarium,  that  is,  on  corneas  that  are  seriously  diseased.  Treatment  consists  in 
oj3ening  or  in  excising  the  vesicle,  atropin  and  cocain  if  the  pain  and  photophobia  are 
severe,  and  protection  from  germs  by  antiseptic  bandage  ;  yellow  ointment  may  be  used 
after  all  inflammatory  symptoms  have  disappeared. 

{d)  Ulcers  from  General  Diseases. 

(a)  Keratitis  e  Lagophthalmo. — Many  people  do  not  com- 
pletely protect  the  eye  by  the  lids  during  sleep.  The  cornea  is 
perhaps  not  injured  by  this,  because  the  eye  of  the  sleeping  person 
turns  upward  and  the  cornea  lies  beneath  the  upper  lid  in  any  case; 
but  if,  under  certain  circumstances  (/.  166)  the  protection  to  the 
eye  is  so  insufficient  that  a  bit  of  the  cornea  remains  uncovered 
during  sleep,  the  corneal  epithelium  on  this  area  becomes  too  dry 
and  perishes,  and  the  result  is  a  keratitis  e  lagophthalmo.  It  is 
evident  that  this  will  result  the  easier  if  the  cornea  is  at  the  same 
time  insensitive  (/.  2^8),  or  if  the  integrity  of  the  corneal  tissue  has 
suffered  very  deeply  by  some  great  exhaustion  of  the  whole  body. 
The  first  condition,  due  to  lack  of  sensation  in  the  cornea,  may  result 
from  any  disease  of  the  brain  causing  paralysis  of  the  facial  or  tri- 
geminal nerves.  The  second  condition,  due  to  some  profound  nu- 
tritive disturbance,  may  result  in  persons  who  have  lain  in  a  coma- 
tose condition  for  a  long  time — for  example,  in  typhoid  fever, 
uremic  coma,  or  in  the  prolonged  agony  of  carcinoma.  This  corneal 
ulcer  is  distinguished  by  its  location  at  the  lower  edge  of  the 
cornea,  by  its  sharply  divided  upper  edge  parallel  to  the  margin  of 
the  upper  lid,  and,  finally,  by  the  fact  that  a  dry  scale  is  first  pro- 


240  DISEASES    OF   THE    CORNEA. 

duced,  the  ulcer  not  being  visible  until  this  scale  is  thrown  off. 
Of  course,  there  must  be  a  positive  proof  that  the  ulcerated  portion 
of  the  cornea  has  been  actually  exposed  to  desiccation.  Treatment 
must  be  directed  to  protection  of  the  cornea  by  the  lids,  either  by 
means  of  a  bandage,  or,  if  this  does  not  suffice,  by  an  operation 
(/.  1^2)  ;  general  principles,  of  course,  apply. 

(;3)  Keratomalacia  Infantum,  Xerosis  Marantica. — The  disease  appears 
usually,  although  not  always,  as  we  might  expect  from  the  name,  in  children  during  the 
first  year  of  life.  The  patient  is  always  severely  ill,  either  from  scarlet  fever  or  syphilis, 
or  from  some  profuse  diarrhea  which  has  brought  him  to  the  edge  of  the  grave.  The 
affection  of  the  cornea  begins  with  cloudiness  and  looseness  of  tlie  epithelium  below  the 
palpebral  fissure.  The  conjunctiva  is  at  the  same  time  in  that  condition  described  on  /. 
21J  as  xerosis  epithelialis.  The  disease  extends  rapidly  within  the  cornea,  which  be- 
comes necrotic  without  the  inflammatory  reaction  that  ought  to  accompany  such  destruc- 
tion. As  the  profound  prostration  of  the  patient  often  prevents  the  eyelids  from  being 
completely  closed,  it  is  evident  that  the  danger  to  the  cornea  is  so  much  the  more  in- 
creased. 

The  prognosis  is  bad.  Many  such  patients  succumb  to  their  disease.  If  recovery 
should  take  place,  the  corneal  ulcer  heals  with  several  disturbing  scars.  Treatment 
must  be  directed  to  the  preservation  of  the  patient's  strength  first  of  all,  then  to  disin- 
fection, protection,  and  to  encouragement  of  nutrition  in  the  cornea.  For  the  last  pur- 
pose warm  compresses  are  very  serviceable. 

Corneal  Necrosis  after  Glaucoma. — When  glaucoma  {(/.  7.)  has  run  its  complete 
course,  the  affected  eye  is  so  radically  changed  and  its  nutritive  condition  is  so  impover- 
ished that  the  cornea  may  suppurate  and  die.  How  much  the  anesthesia  of  the  cornea 
may  be  considered,  along  with  the  impaired  nutrition,  as  a  cause  of  this  necrosis  cannot 
at  present  be  decided. 


3.  LNFLAMMATIONS  WITHOUT  THE  FORMATION  OF  ULCER. 

{a)  Pannus  is  a  new  growth  of  connective  tissue  between  the 
epithelium  and  Bowman's  membrane,  provided  more  or  less  abun- 
dantly with  blood-vessels.  If  pannus  begins  superficially,  it  is  not 
always  restricted  to  this  layer  of  the  cornea  {Fig.  86),  but  if  the 
disease  continues  long  enough  it  may  affect  the  cornea  proper,  very 
clearly  demonstrable,  as  Saemisch  says,  by  the  fact  that  the  vessels 
lying  within  the  different  layers  may  be  seen  crossing  above  or 
below  each  other. 

Raehlmann  thinks  the  condition  is  somewhat  different.  He  found  that  pannus  began 
beneath,  not  on,  Bowman's  membrane,  and  that  the  disease  spread  from  here  toward  the 
surface  and  toward  the  depth.  For  example,  collections  of  cells  develop  beneath  Bow- 
man's membrane ;  these  are  genuine  follicles  provided  with  an  envelope ;  they  raise 
Bowman's  membrane  and  the  epithelium,  and  then  break  out  in  small  ulcers.  These 
ulcers,  however,  play  no  part  clinically;  they  need  no  particular  treatment,  and  do  not 
prohibit  us  from  considering  pannus  among  the  "  inflammations  without  ulcer." 


PAN  N  us.  241 

Raehlmann  found,  further,  that  a  pronounced  pannus  was  developed  with  special  layers, 
and  that  these  layers  consisted  in  part  of  sclerosed  (cicatricial)  connective  tissue  and  in 
part  of  round  cells ;  he  considered  that  the  layers  stood  for  a  gradual  development  of 
new  tissue — the  deposits  of  round  cells  indicating  the  new  layers,  the  connective  tissue, 
the  old.  The  cornea  becomes  noticeably  thickened  by  these  numerous  layers,  reaching 
twice  the  normal  thickness.  In  spite  of  this,  however,  it  has  no  greater  resistance,  but 
on  the  contrary  may  be  weakened  by  it,  and  on  this  account  may  easily  yield  to  the  in- 
ternal tension  of  the  eye,  a  condition  known  as  ectasia  (/.  26 1').  The  thickness  of  the 
pannus  tissue  decreases  from  the  edge  of  the  cornea  toward  its  center ;  pannus  at  the 
edge  of  the  cornea  may  extend  even  to  Descemet's  membrane;  but  at  the  center  of  the 
cornea  only  the  anterior  layers  immediately  below  Bowman's  membrane  are  infiltrated. 
The  diminution  in  thickness  from  the  edge  toward  the  center  of  the  cornea  is  so  sudden 
that  the  pannused  surface  may  be  accurately  marked  off  from  the  healthy  tissue. 


^pMeliiim. 


"■"„ ^  \  »;-  •- =^".>;^;' ~-'^.^-  ^.ja. 


-Jh/tnus  tusite 


-SBowma/us 


"~  '"  -^      JCmibrane 


— Sukstantiaproprit. 


Fig.  86. — Pannus.     (After  Pagenstecher  and  Genth.) 
There  are  four  blood-vessels  to  be  seen  in  the  section. 

The  vessels  in  pannus  are  offshoots  from  the  marginal  network, 
but  occasionally  come  from  the  larger  vessels  arising  far  back  from 
the  conjunctiva.  For  this  reason  it  is  possible  to  follow  a  blood- 
vessel past  the  sclero-corneal  margin  into  the  conjunctiva. 

Clinically,  pannus  appears  as  an  inflammation  of  the  cornea,  in 
which  large  areas  are  clouded  and  penetrated  by  superficial  vascu- 
larization. Therefore  the  surface  of  the  cornea  is  not  smooth  but 
rough,  uneven,  filled  with  ridges  which  seem  to  be  formed  from  the 
surface  of  the  cornea  by  the  thicker  vessels.  If  this  vascular 
formation  is  so  luxurious  that  the  red  of  the  blood-vessels  pre- 
dominates over  the  gray  of  the  pannused  tissue,  the  condition  is 
called  pannus  crassus  or  carnosus.  If  the  mesh  in  the  vascular  net- 
work is  coarse,  the  condition  xs, pannus  tenuis.  There  are  two  kinds 
of  ^d^nnns,  pafiiius  trachojnatosiis  divxd  pajinus  eczematosus.  The  first 
has  been  described  on  /.  201 ;  it  is  distinguished  by  the  fact  that  it 
attacks  the  upper  half  of  the  cornea  in  an  eye  already  suffering 
from  a  trachomatous  inflammation  of  the  conjunctiva  {Fig.  8j). 
16 


242  DISEASES    OF   THE    CORNEA. 

Pannus  eczematosiis  has  been  described  on  /.  2j;2  under  the 
name  of  phlyctenular  marginal  pannus  or  keratitis  superficialis 
vasculosa.  It  may  be  supplementarily  remarked  that  at  the  border 
between  the  transparent  and  pannused  cornea  new  groups  of  gray- 
ish dots,  small  infiltrates  or  phlyctenules,  may  appear.  The  result 
of  this  is  that  the  vascular  network  extends  into  the  hitherto 
transparent  cornea,  and  in  doing  so  changes  the  marginal  pannus 
into  an  eczematous  pannus,  or  under  certain  conditions  may  spread 
over  the  entire  cornea. 

Panmis  traumaticus  may  be  described  as  still  a  third  variety.  It 
occurs  after  long-standing  irritation  of  the  cornea  by  inverted 
lashes  (trichiasis)  and  lids  (entropium) ;  ulcers  are  not  always 
formed,  but  only  a  superficial  cloudiness — pannus,  due  to  the  blood- 
vessels. Of  course,  both  conditions,  pannus  and  ulcers,  may  occur 
together,   especially  if  not   only  trichiasis    but    also    eczema    and 

trachoma  have  led  up  to  it.  In  trau- 
matic pannus  the  sharp  outline  be- 
tween healthy  and  unhealthy  tissue, 
and  the  rough,  raw  surface,  with  the 
thickening  of  the  cornea,  are  all  lack- 
ing. 

Treatment  of  traumatic  pannus 
consists  obviously  in  curing  the  tri- 

FiG.    87. — Pannus  Trachomatosus.  i   •      •  nru         u  i"    _       r  i.u 

{After  sichen  chiasis.      1  he  absorption  of  the  pan- 

nused  tissue  can  be  encouraged  by 
massage  with  yellow  ointment ;  the  same  method  is  applicable  in 
eczematous  pannus.  Trachomatous  pannus  heals  without  special 
treatment  if  the  trachoma  of  the  conjunctiva  can  be  cured.  In  many 
cases,  to  be  sure,  the  pannus  outlasts  the  conjunctival  disease ;  under 
such  circumstances  the  various  stimulating  applications,  such  as 
yellow  ointment,  tincture  of  opium,  and  sulfate  of  copper,  and,  as  a 
last  resort,  circumcision,  must  be  tried.  This  last  name  indicates  the 
operative  excision  of  a  strip  of  conjunctiva  about  2  mm.  wide,  parallel 
to  the  edge  of  the  cornea ;  the  vessels  running  to  the  cornea  are  in 
this  way  exposed  or  cut  through,  and  as  the  wound  cicatrizes  they 
become  obliterated.  Another  method  deserves  mention,  namely, 
the  production  of  a  conjunctival  blennorrhea  by  touching  the  con- 
junctiva with  an  extract  of  jequirity  seeds  (paternoster  beads).  It 
was  quite  accidentally  observed  that  an  old  pannus  healed  in  a 
remarkable  manner  after  the  cornea  had  been  excessively  inflamed 


KERATITIS    PARENCHYMATOSA.  243 

by  any  foreign  substance.  Even  this  method  may  fail,  however,  if 
the  opacity  depends  not  upon  a  fresh  pannus  but  upon  cicatricial 
connective  tissue. 

{b)  Keratitis  Parenchymatosa  {Keratitis  interstitialis  diffusa). — 
The  center  of  the  substantia  propria  of  the  cornea  becomes  opaque 
after  a  moderate  irritation  and  pericorneal  injection  ;  these  opacities 
increase  slowly  but  surely,  so  that  after  several  weeks  the  entire 
cornea  is  saturated  with  them.  Spoke-like  opacities  may  occasion- 
ally be  seen ;  all  opacities  are  not  of  the  same  density,  so  that  by 
superficial  observation  many  parts  of  the  cornea  may  appear  quite 
unaffected.  Nevertheless,  when  the  disease  is  at  its  height,  focal 
illumination  will  reveal  more  or  less  delicate  opacities,  even  in  such 
apparently  unaffected  areas.  Without  a  lens  th^  cornea  appears  dif- 
fusely opaque.  In  other  cases, — this  is  the  rule  according  to 
Horner, — the  disease  begins  not  at  the  center  of  the  cornea,  but  at 
the  margin,  and  advances  step  by  step  from  all  sides  toward  the 
center.  Since  the  affected  portions  of  the  cornea  are  thicker  than 
the  healthy  ones,  the  transition  is  often  very  abrupt.  The  epithe- 
lium is  changed  at  the  same  time.  At  first  it  appears  dull,  later 
stippled,  but  never  shows  loss  of  substance.  Ulceration  is  never  a 
characteristic  of  this  disease. 

The  disease  is  not  restricted  to  the  cornea  alone ;  deeper  portions 
of  the  eye,  the  iris  especially,  may  be  affected  sympathetically,  the 
production  of  posterior  synechiae  being  evidence  of  this.  In  fact, 
any  series  of  cases  may  show  a  cyclitis  or  a  choroiditis,  with  all 
their  destructive  consequences  to  the  normal  condition  of  the  globe 
and  the  nutrition  of  the  lens  and  vitreous.  The  involvement  of  the 
deeper  tissues  of  the  eye  is  often  not  recognizable  until  the  clear- 
ing up  of  the  cornea  which  has  meanwhile  resulted  allows  the 
deeper  parts  to  be  inspected. 

Opacities  of  the  cornea  due  to  migration  of  round  cells  begin 
after  several  months  to  clear  up  from  the  margin  by  means  of  new- 
formed  corneal  vessels.  The  number  of  these  vessels  varies,  so 
much  so,  in  fact,  that  one  is  inclined  to  call  each  case  a  particular 
disease.  It  must  be  remembered,  however,  that  few  cases  run  their 
course  entirely  without  vascular  formation,  and  that  the  recession 
of  the  opacities  results  quicker  and  more  completely  the  more 
abundant  this  vascularization.  These  vessels  are  distinguished  from 
the  superficial  vessels  of  pannus  in  three  ways  : — 

(i)  They  do  not,  like  pannus  vessels,  spring  from  the   marginal 


244  DISEASES    OF    THE    CORNEA. 

network  of  the  conjunctiva,  but  from  a  network  lying  deep  within 
the  sclera,  so  that  they  can  be  followed  only  to  the  sclero-corneal 
margin  ;  the  pannus  vessels,  on  the  contrary,  are  easily  traceable 
beyond  the  scleral  margin  into  the  conjunctiva. 

(2)  They  are  not,  like  superficial  pannus  vessels,  covered  by 
epithelium  alone,  but  by  the  opaque  cornea.  They  are,  therefore, 
less  red  and  less  visible  than  pannus  vessels,  and  are  best  seen  by 
illumination  from  behind  (/.  100). 

(3)  They  are  thin  and  run  in  parallel  groups,  while  pannus  ves- 
sels, at  least  those  in  eczematous  and  traumatic  pannus,  are  of 
different  sizes  and  spread  out  like  branches  of  a  tree. 

It  does  occasionally  happen  that  in  keratitis  parenchymatosa  superficial  vessels  spring 
from  the  conjunctival  net\tork. 

The  condition  of  irritation  is  just  as  dissimilar  as  is  the  forma- 
tion of  blood-vessels.  As  a  rule  there  is  neither  photophobia  nor 
pain,  in  spite  of  pronounced  injection  about  the  cornea.  This  in- 
flammatory redness  about  the  cornea  is,  however,  as  much  to  be 
desired  as  the  development  of  blood-vessels  within  the  cornea, 
since  it  indicates  the  more  rapid  progress  of  the  disease;  although 
even  in  such  cases  the  disease  may  be  expected  to  last  several 
months,  and  unfavorable  cases  may  last  for  years,  with  alternate 
improvement  and  relapse. 

Keratitis  parenchymatosa  is  evidence  of  general  infection.  In 
proof  of  this  we  have  the  fact  that  in  at  least  80  per  cent,  of  cases, 
according  to  Horner,  both  eyes  are  attacked,  although  not  neces- 
sarily simultaneously.  Besides  this,  Hutchinson  has  shown  that 
inherited  syphilis  is  undoubtedly  the  cause  of  the  condition  and  is 
demonstrable  in  about  two-thirds  of  all  cases.  It  is  therefore  best 
to  search  for  other  signs  of  inherited  syphilis.  Among  them  may 
be  mentioned  "  Hutchinson's  teeth" — a  condition  characterized  by 
an  irregularity  of  the  upper  incisors,  the  edges  of  which  are 
changed  from  a  horizontal  straight  line  into  an  upcurved  arch. 
Other  signs  are  a  permanent  thickening  of  the  periosteum,  particu- 
larly on  the  shin,  painless  joint  affection,  glandular  swellings  and 
cicatrices,  scars  and  malformations  of  the  palate,  and  rapidly  de- 
veloping deafness.  Since  inherited  syphilis  lies  at  the  bottom  of 
the  disease,  it  is  found  particularly  in  young  persons  between  the 
fifth  and  twentieth  year;  but  it  is  not  quite  clear  why  female  chil- 
dren should  be  attacked  nearly  twice  as  commonly  as  male  children. 


KERATITIS    PARENCHYMATOSA.  245 

The  diagnosis  is  easy  in  the  fully  developed  condition  ;  the  affec- 
tion in  both  eyes,  the  profuse  opacity  of  the  entire  cornea,  which  is 
salmon-gray  if  the  vascularization  is  abundant,  or  grayish  if  it  is 
moderate,  the  lack  of  ulceration,  all  produce  a  notjceable  patho- 
logical picture.  On  the  other  hand,  the  diagnosis  is  hard  if  the 
disease  is  found  in  any  of  its  first  stages,  for  so  long  as  there  is 
only  a  marginal  opacity  with  congestion  of  the  neighboring  vascu- 
lar network,  there  is  danger  of  confusing  the  condition  with  kera- 
titis eczematosa ;  the  progress  of  the  disease  must  be  our  guide. 

Keratitis  parenchymatosa  was  at  one  time  considered  of  scrofulous  origin.  This  old 
view  has  recently  received  more  attention,  inasmuch  as  many  authors  think  that  a  certain 
proportion  of  the  cases  result  from  scrofula  or  modified  tuberculosis.  Acquired  syphilis 
is  said  to  be  able  to  produce  keratitis  parenchymatosa. 

The  prognosis  is  unfavorable,  and  the  patient  must  be  told  that 
his  trouble  will  last  for  months  or  years,  that  the  second  eye  will 
most  probably  be  attacked,  and  that  a  restoration  of  the  visual 
acuity  unimpaired  is  scarcely  to  be  hoped  for,  especially  if  the 
patient  is  not  very  young.  There  is  alinost  always  left  some  cor- 
neal opacity,  in  which  one  can  see  several  fine  blood-vessels  with  a 
magnifying  glass,  and  from  the  presence  of  these  unusually  fine 
vessels  one  can  detect  the  evidence  of  a  keratitis  parenchymatosa 
years  or  even  decades  afterward.  Fortunately,  coinplete  loss  of 
vision  is  seldom  to  be  feared. 

Treatment  has  little  influence  upon  the  course  of  the  disease; 
if  syphilis,  either  inherited  or  acquired,  can  be  proven,  an  impres- 
sive course  of  mercurial  inunction  should  be  tried,  unless  anemia 
or  general  exhaustion  make  the  method  dangerous.  In  such  a 
case  mercurial  treatment  must  be  abandoned,  and  the  physician 
should  resort  at  once  to  iodid  of  potassium,  iodid  of  iron,  cod-liver 
oil,  baths,  and  fresh  air.  Local  treatment  must  be  restricted  to 
atropin,  warm  compresses,  and  protective  glasses.  Atropin  over- 
comes the  iritis  and  breaks  up  the  posterior  synechias,  moist  heat 
encourages  vascularization  and  thereby  shortens  the  disease.  The 
tentative  use  of  massage  with  yellow  ointment  to  hasten  the  ab- 
sorption of  the  infiltration  should  not  be  resorted  to  until  the 
disease  has  passed  the  climax  and  the  clearing  up  has  begun. 
If  massage  is  well  borne,  more  energetic  means  may  be  tried, 
and  the  yellow  ointment  displaced  after  several  weeks  by  other 
stimulants,  such  as  calomel  powder  or  equal  parts  of  turpentine 
and  olive  oil. 


246  DISEASES    OF    THE    CORNEA. 

{c)  Keratitis  parenchymatosa  circumscripta  is  a  rare  inflammation  of  the  cornea 
that  has  many  signs  in  common  with  keratitis  parenchymatosa.  It  begins  as  a  grayish 
opacity  at  the  center  of  the  cornea,  rather  in  the  middle  layers.  The  opacity  extends  to 
the  epithelium  and  to  the  posterior  surface  of  the  cornea.  The  marginal  portions  of  the 
cornea  remain  free.  After  several  weeks  or  even  months  have  passed,  the  opacity  be- 
gins to  clear,  but  this  process  is  seldom  completed,  and  there  is  apt  to  be  left  an  incura- 
ble corneal  deposit  exactly  in  front  of  the  pupil.  The  irritation  is  slight,  and  may  be  so 
completely  absent  that  at  the  first  inspection  no  inflammation  is  seen,  and  one  thinks  to 
have  found  a  large  leukoma  on  the  cornea.  Vascularization  does  not  take  place,  or  if  it 
does,  it  is  very  much  less  than  in  keratitis  parenchymatosa.  In  severe  cases  the  cloudy 
cornea  is  insensitive  ;  if  sensation  returns,  however,  it  is  an  indication  of  a  speedy  im- 
provement. The  disease  is  unilateral,  and  usually  attacks  elderly  persons,  men  twice  as 
often  as  women.  The  opacity  is  said  to  depend  not  on  round-cell  infiltrations,  but  on 
cloudiness  and  disintegration  of  the  fixed  corneal  cells  and  on  swelling  and  relaxation 
of  the  fibers.  Little  is  known  of  the  cause  of  the  disease.  Egger  thinks  that  a  weak 
physical  condition  with  impairment  of  the  general  nutrition  must  be  an  important  factor. 

The  prognosis,  considering  the  length  of  the  disease,  the  fact  that  incurable  opacities 
are  almost  always  left,  and  that  the  iris  shows  a  tendency  to  be  sympathetically  affected, 
must  be  considered  unfavorable.  Treatment  should  seek  to  improve  the  general  con- 
dition by  a  proper  regimen  ;  locally,  the  persistent  use  of  moist  applications  may  stimu- 
late vascularization,  and  atropin  should  be  applied  in  order  to  assure  the  preservation  of  the 
iris  ;  when  the  irritation  has  completely  subsided,  massage  with  yellow  ointment  should 
be  begun.  Caution  must  be  observed  in  resorting  to  operative  interference,  as  iridectomy, 
for  example  ;  the  eye  seems  to  resent  this,  as  I  can  confirm  from  unfortunate  experience 
in  the  matter,  and  the  opacity  progresses  rapidly  into  the  hitherto  peripheral  portion  of 
the  cornea  lying  in  front  of  the  artificial  pupil.  This  new  cloudiness  will  probably 
clear  up  in  a  few  weeks,  but  the  patient  does  not  relish  the  experience. 

[(/)  Keratitis  Scleroticans. — This  disease  is  characterized  by  an  involvement  of  the 
cornea  in  an  inflammation  of  the  sclera.  The  corneal  opacity  is  of  a  somewhat  triangu- 
lar shape,  its  base  lying  toward  the  portion  of  the  cornea  already  inflamed,  its  apex 
extending  more  or  less  into  the  cornea.  The  disease  is  usually  chronic,  with  very  little 
or  no  irritation,  with  very  little  or  no  vascularization,  and  without  ulceration.  So  long 
as  the  clouded  area  does  not  extend  its  apex  into  the  region  of  the  pupil,  the  disease 
may  go  on  without  comment.  The  opacity  recedes,  also  with  equal  slowness,  but  a 
complete  clearance  takes  place  only  at  the  central  edge  of  the  clouded  area.  The 
marginal  portions  remain  opaque,  retaining  an  appearance  as  if  the  sclera  had  in  this 
place  grown  into  the  cornea  itself. 

The  prognosis  is  favorable  if,  as  is  usually  the  case,  the  disease  is  restricted  to  the 
edge  of  the  cornea.  It  may  last  for  months  or  years.  Treatment  should  be  directed 
to  the  cure  of  the  inflammation  of  the  sclera  (/.  ^62) ;  atropin  and  moist  heat  have  been 
advised,  but  stimulants  and  operations  should  be  avoided. 

(e)  Keratitis  Punctata  Profunda. — Just  as  the  iris  is  sympa- 
thetically affected  in  severe  corneal  inflammation,  so  may  an  inflam- 
mation of  the  iris  leave  its  mark  upon  the  cornea.  This  is  quite  a 
usual  result  in  iritis  serosa  {p.sjf);  indeed,  "  keratitis  punctata 
profunda "  itself  is  often  the  only  sign  of  such  an  iritis.  The 
changes  on  the  cornea  consist  in  minute  points  sometimes  infre- 


WOUNDS. 


247 


quent,  sometimes  innumerable,  upon  the  posterior  surface  of  the 
cornea — the  so-called  deposits  upon  Descemet's  membrane.  These 
dots  may  be  large  or  small ;  the  larger  ones  seen  by  the  magnif}-ing 
glass  look  like  \-ello\vish  fat  droplets.  At  times  the  deposit  is 
arranged  in  the  form  of  a  triangle  (/v^.  SS).  If  these  deposits  re- 
main ver\'  long  the\'  are  apt  to  produce 
a  disturbance  of  the  nutrition  and  a  sub- 
sequent opacity  in  the  hindermost  layers 
of  the  cornea  which  does  not  always  dis- 
appear, even  though  the  iritis  serosa  has 
been  meanwhile  cured  and  the  deposit 
itself  absorbed. 


The 


.     I.  >■       -vr        1  ■■   1  Fig.  8S — nErosrrs    upon  the   Pos- 

-It  upon  ••  Descemct  s   Membrane      has  ^.^^^^^^    ^^^^.^.^  ^^  .^^^^  Coknea. 


such  a  characteristic  appearance  tliat  we  are  at  once  [After  hctleship.) 

iustitled  in  ascribini^  the  seat  of  an  opacity  to  the  pos- 
terior surl"ace  of  the  cornea.  This,  of  course,  does  not  release  the  physician  from  the  duty 
of  determining  by  exact  ojnical  methods  in  what  particular  layers  of  tlie  cornea  the  opacity 
actually  lies.  This  can  be  done  by  means  of  focal  illumination,  the  magnifying  glass,  and 
experience.  If  there  is  the  least  doubt,  the  phenomenon  of  the  parallax  must  be  used,  that 
is.  the  apparent  movement  of  the  opacity  against  the  surface  of  the  cornea  as  a  result  of 
movement  of  the  physician's  head.  It  is  understC)od  that  the  surface  of  the  cornea  must  be 
Well  recognizable,  as  it  often  is,  by  the  way,  by  the  minute  air  vesicles  or  collections  of 
epithelium,  t"at,  and  mucus,  all  of  which  are  rendered  visible  when  the  magnifying  glass 
is  used.  If  the  surface  of  the  cornea  should  happen  to  be  clean  it  maybeeasilv  itlentihed 
by  dusting  on  it  a  few  grains  of  calomel  or  iodoform,  or  by  smearing  it  with  a  bit  of  yellow- 
ointment.  In  rare  cases  similar  droplets  to  those  deposited  on  Descemet's  membrane 
mav  be  seen  strewn  on  the  anterior  surtace  of  the  lens. 


II.  INJURIES. 

The  cornea  is  very  often  injured,  partly  because  it  is  so  exposed, 
partly  because  it  is  so  tense  that  it  cannot  yield  to  any  blow.  That 
portion  K'iiig  within  the  palpebral  fissure  is,  of  course,  the  area 
most  often  inv^olved. 

I.  WOUNDS. 
These  are  produced  in  innumerable  ways,  b)'  scratches,  for  ex- 
ample, which  little  children  make  with  their  finger-nails  on  the  e\-cs 
of  their  mothers  or  nurses.  Similar  wounds  may  be  made  b\'  twigs, 
which  may  strike  the  eye  of  an  unobservant  traveler  in  the  woods. 
Larger  wounds  may  be  made  by  the  end  of  a  vigorously  wielded 
whipcord  or  by  the  blow  of  a  cane   or  of  the  fist,  especially  if  an 


248  DISEASES   OF   THE   CORNEA- 

eye  glass  is  broken  and  the  fragments  shattered  against  the  eyeball. 
The  signs  of  a  corneal  wound  are  the  following :  The  patient  appears 
with  an  eye  flooded  with  tears  and  afraid  of  light ;  he  complains  of 
great  pain,  or  of  the  feeling  that  his  eye  has  been  scratched,  or  that 
there  is  a  foreign  body  in  it.  The  eye  seems  reddened,  there  is 
ciliary'  injection.  Looking  at  the  surface  of  the  cornea  {p.  g6),  a 
loss  of  substance  is  seen,  but  the  ground  is  clear  and  unclouded. 
If  the  loss  of  substance  is  so  small  that  it  cannot  be  seen  with  the 
naked  eye,  focal  illumination  and  the  magnifying  glass  (/>.  ^S)  or 
the  fluorescin  test  {p.  222)  must  be  used. 

The  prognosis  depends  uf>on  the  location  and  depth  of  the 
wound  and  upon  the  nature  of  any  accidental  infection.  A  simple 
uninfected  loss  of  epithelium  will  heal  without  a  trace  within 
twenty-four  hours,  and  is  therefore  of  no  moment,  even  though  it 
lies  within  the  pupillary  area.  But  the  wound  extending  into  the 
substantia  propria  of  the  cornea  leaves  a  scar,  and  is  therefore  of 
great  moment,  although  it  may  not  lie  in  any  jjortion  of  the  cornea 
used  for  optical  purposes.  Still  more  serious-  are  wounds  of  the 
entire  thickness  of  the  cornea;  these  are  called  perforating  wounds. 
Immediately  after  a  perforation  of  the  cornea  the  aqueous  escapes 
and  the  anterior  chamber  is  obliterated.  When  the  edges  of  the 
wound  are  bathed  in  the  aqueous  they  become  clouded  and  swollen  ; 
this  cloudiness,  either  diffuse  or  striated,  may  extend  more  or  less 
into  the  adjacent  tissue.  Usually  the  central  layers  of  the  cornea 
are  quickly  united,  the  anterior  chamber  is  reproduced,  the  iris 
returns  to  its  natural  position,  the  epithelium  grows  from  without 
into  the  wound,  and  under  the  protection  of  this  new-formed  cover 
the  cleft  is  filled  up  again.  If  the  wound  is  large,  however,  the 
escape  of  the  aqueous  is  so  sudden  that  the  iris  prolapses.  The 
results  of  such  an  accident  are  discussed  on  p.  ^57, 

It  very  often  happens  that  bacteria  enter  the  wound,  either 
csLTued  by  the  object  producing  the  injury,  or  absorbed  from  the 
conjunctiva  or  the  edge  of  the  lid;  or  the  wound  may  be  subse- 
quently infected  by  dirty  fingers  or  pocket  handkerchiefs,  or  by 
dirty  water  that  has  been  used  to  bathe  the  eye.  The  evidence  of 
such  infection  is  a  cloudiness  of  its  edges  and  their  surroundings. 
We  have  now  all  the  manifestations  of  an  ulcer,  a  keratitis  traumat- 
ica. The  appearance  and  course  of  this  traumatic  ulcer  cannot  be 
SLCCuraXely  given,  since  they  depend  so  much  upon  the  nature  as 
well  as  upon  the  number  of  the  germs  that  have  found  entrance. 


FOREIGN    BODIES. 


249 


If,  for  example,  the  injured  person  is  suffering  from  an  inflammation 
of  the  tear  sac,  the  result  will  be  "  ulcus  serpens  ; "  if  he  has  an  old 
and  indolent  conjunctivitis,  the  result  would  be  an  ulcer  that  we 
may  call  catarrhal  ( /.  2j^  for  lack  of  a  better  name. 

Treatment  of  a  fresh,  uninfected,  and  smaller  wound  is  met  by 
a  simple  antiseptic  bandage.  If  the  wound  is  larger  and  if  there  is 
much  irritation,  atropin  may  be  used  in  addition.  If  the  iris  has 
prolapsed  the  effort  should  be  made  to  replace  it  by  means  of  a 
small  spatula,  and  to  retain  it  in  place  by  eserin, 
a  bandage,  and  rest.  If  this  is  not  successful  the 
prolapsed  portion  must  be  seized  with  an  iris 
forceps  {Fig.  8g),  drawn  out,  and  e.xcised  with  one 
stroke  of  the  scissors — in  short,  an  iridectomy 
{p.  286)  is  completed. 


2.  FOREIGN  BODIES  (CORPORA  ALIENA). 
By  far  the  most  frequent  injury  to  the  cornea 
is  made  by  a  foreign  body.  Among  the  foreign 
bodies  bits  of  metal,  and  among  these  bits  of 
metal  little  iron  chips  are  the  commonest.  Every 
foreign  body  produces  the  well-known  signs  of  a 
corneal  inflammation,  its  degree  depending  alto- 
gether upon  the  character  of  the  foreign  body. 
If  the  foreign  body  is  covered  with  bacteria,  as 
is  usually  the  case,  the  result  is  an  ulcus  serpens. 
If  it  is  free  from  bacteria,  as  is  the  case  in  bits 
of  molten  metal,  the  effect  is  only  a  mechanical, 
or  a  thermal,  or  a  chemical  one.  The  use  of  the 
actual  cautery  has  often  enough  proven  that  the 
thermal  effect  is  no  more  than  that  of  an  immedi- 
ate and  simple  burn,  and  small  aseptic  cauten,'  wounds  heal  with 
unusual  promptitude.  The  chemical  effect  of  a  bit  of  iron  is 
characterized  by  a  small,  encircling,  brownish  ring,  indicating  that 
the  directly  adjacent  tissue  of  the  cornea  has  been  discolored  by  the 
oxid  of  iron  (rust).  Even  the  inflammation  produced  by  bits  of  iron 
or  copper  may  be  largely  ascribed  to  their  chemical  effect  If  such 
an  action  must  be  excluded,  in  the  case  of  bits  of  glass,  for  example, 
the  mechanical  effect  is.  nevertheless,  sufficient  to  produce  an  irri- 
tation, since  the  weight  and  movements  of  the  lids  will  press  the 
foreign  body  into  the  cornea,  so  well  supplied  with  ner\'es. 


v. 

Fig.  89. — Iris  Forceps. 


250  DISEASES    OF   THE   CORNEA. 

It  is  not  always  easy  to  find  a  foreign  body,  especially  if  the 
patient  is  not  sure  that  it  is  in  the  cornea.  It  often  happens,  there- 
fore, that  the  foreign  body  is  overlooked.  This  may  be  easily 
avoided  by  a  rigid  adherence  to  the  systematic  examination  recom- 
mended on  p.  i^i,  from  the  surface  to  the  interior  of  the  eye.  The 
experienced  physician  will  probably  suspect  the  presence  of  a 
foreign  body,  even  though  the  patient  makes  no  mention  of  it,  by 
the  peculiar,  delicate  rose-red  injection  in  the  cornea.  Dark  foreign 
bodies  are  best  seen  against  the  comparatively  light  background  of 
the  iris.  If  a  foreign  body  is  not  seen  by  simple  inspection,  focal 
illumination  (/.  g8),  transillumination  {p.  118),  and  the  fluorescin 
test,  must  each  in  turn  be  used.  When  fluorescin  is  applied,  the 
presence  of  the  foreign  body  will  be  betrayed  by  the  greenish  area 
which  surrounds  it. 

If  the  foreign  body  is  not  removed,  it  never 
altogether  heals  in  situ.  There  is  almost  always 
about  it  a  cell-infiltration  which  destroys  the 
tissue  immediately  adjacent,  so  that  the  foreign 
body  is  loosened  and  may  be  washed  away  by 
the  tears.  This  process,  of  course,  takes  place 
slowly,  with  all  the  phenomena  of  inflammation, 
and  thus  every  opportunity  for  infection  is  offered. 
Treatment  demands  immediate  removal  of  the 
foreign  body;  this  is  accomplished  by  means  of  a 

Fig.  90.— Spud  FOR  Re-  v-       i  j     /  r-  \         T-u 

MOVING  Foreign     small   curcttc,  chisel,  or   spud    (rior.  no),      ihe 

Bodies.  '  ... 

cornea  should  be  made  insensitive  by  an  aseptic 
cocain  solution.  The  patient  is  then  told  to  look  steadily  at  some 
point.  The  left  hand  of  the  surgeon  raises  the  upper  lid  and 
presses  gently  upon  the  eyeball  in  order  to  keep  it  steady.  In 
removing  foreign  bodies  the  use  of  the  lens  and  of  focal  illumina- 
tion is  most  emphatically  to  be  recommended.  By  this  means  the 
very  minutest  particle  can  be  removed  without  any  appreciable 
injury  to  the  cornea  itself.  The  lens  should  be  held  between  the 
index  finger  and  thumb  of  the  left  hand,  while  the  middle  and  ring 
fingers  raise  the  lid  and  press  upon  the  eyeball.  The  illumination 
must  be  supplied  by  an  assistant;  if  there  is  no  assistant  at  call,  a 
very  good  device  may  be  made  by  fitting  a  convex  lens  to  a  lamp 
so  that  the  light  is  properly  thrown  upon  the  field  of  operation. 
If  the  foreign  body  lies  very  deep  in  the  cornea,  it  maybe  crowded 
into  the  anterior  chamber  by  unskilful  manipulation.     This  is  a 


BURNS FKIGERATION — ARCUS    SENILIS.  25  I 

serious  accident.  The  foreign  body  then  falls  into  the  iritic  angle 
and  can  no  longer  be  seen  by  the  surgeon.  It  is  best,  therefore,  if 
the  foreign  body  is  close  to  or  within  the  anterior  chamber  to  in- 
troduce a  small  keratome  {Fig.  yg,  p.  2ij),  such  as  is  used  for  iri- 
dectomy, into  the  anterior  chamber,  pressing  the  flat  of  the  blade 
against  the  posterior  surface  of  the  cornea,  and  then  with  the  sup- 
port thus  offered  to  remove  the  foreign  body.  After  its  removal  a 
corneal  wound  is  left,  and  this  must  be  treated  according  to  the 
rules  already  given. 

3.  BURNS. 

Steam,  molten  metal,  explosions  of  powder  and  dynamite,  and,  in 
the  broader  sense  of  the  word,  irritating  chemicals,  usually  strike 
the  lids  and  conjunctiva  as  well  as  the  cornea,  the  conjunctiva,  per- 
haps, being  even  more  seriously  affected  {p.  216).  The  involve- 
ment of  the  cornea  is  recognized  by  a  diffuse  opacity  and  insensi- 
tiveness. 

The  prognosis  depends  upon  the  extent  and  depth  of  the  burn  ; 
if  only  the  epithelium  has  been  destroyed,  complete  restoration 
will  be  effected  without  any  permanent  opacity.  If  the  substantia 
propria  of  the  cornea  is  burned  off  the  whole  tissue  will  slough 
away,  and  the  healing  will  result  with  formation  of  a  cicatrix.  The 
degree  of  anesthesia  is  a  good  criterion  of  the  depth  of  the  burn. 
Treatment  has  been  mentioned  on  /.  216. 

4.  FRIGERATION. 
Cases  have  been  reported  of  ulcers  of  the  center  of  the  cornea 
resulting,  in  the  opinion  of  the  attending  physician,  from  severe  cold. 


III.  CORNEAL  OPACITIES  OF  A  NON-INFLAMIVIATORY 

NATURE. 

I.  Arcus  Senilis  {Geronioxoii). — In  old,  sometimes  even  in  young  persons,  there  is  seen 
a  circular  opacity  of  the  edge  of  the  cornea,  distinguishable  from  other  peripheral  opacities 
by  the  fact  that  the  outermost  portion  remains  transparent.  Its  appearance,  therefore,  is 
that  of  a  grayish-white  ring  about  i.j  to  2  mm.  broad  within  the  cornea,  surrounded  by 
a  very  small  dark  ring  (the  iris)  bordering  on  the  sclera.  The  epithelium  above  this 
opaque  ring  reflects  light  perfectly.  Fuchs"  opinion  is  that  the  opacity  is  due  to  a  deposit 
of  hyaline  material  which  has  settled  from  the  nutrient  lymph  stream  between  the  lamella; 
of  the  cornea  as  an  insoluble  form  of  albumin.  Owing  to  the  peripheral  position  of  the 
arcus  senilis  it  seems  to  have  no  bad  influence  on  vision. 

I  think  that  a  similar  degeneration  occurs  in  the  more  central  portions  of  the  cornea, 


252  DISEASES    OF   THE    CORNEA. 

for  I  have  twice  observed  corneal  opacities  without  any  indication  of  irritation  and  with- 
out any  preceding  inflammation.  Tiiese  opacities  were  unlike  the  rilibon-like  opacities 
(p.  2jj),  since  in  the  former  the  epithelium  reflected  light  perfectly,  the  borders  were 
indistinct,  and  they  extended  over  a  greater  portion  of  the  cornea.  In  the  second  of  my 
cases  this  bilateral  cloudiness  was  coincident  with  an  arcus  senilis  of  unusual  breadth  and 
density. 

2.  Cocain  Opacity. — We  may  well  say  that  cocain,  introduced 
into  ophthalmology  by  KoUer,  has  become  an  indispensable  bless- 
ing. But  even  this  drug,  however  indispensable  it  may  be,  proves 
itself  at  times  a  treacherous  friend,  since  it  annihilates  the  result  of 
many  a  cataract  operation  by  the  incurable  diffuse  opacity  of  the 
cornea  which  it  causes.  If  the  physician  has  not  himself  had  this 
severe  experience  he  must  certainly  have  often  enough  seen  the 
beginnings  of  a  cocain  opacity  in  the  haziness  which  the  surface  of 
the  cornea  assumes.  This  haziness  has,  as  Wuerdinger  shows,  two 
causes : — 

(i)  The  "  lymphatic  anemia,"  and 

(2)  The  desiccation  of  the  uncovered  cornea. 

The  expression,  lymphatic  anemia,  certainly  an  improper  one,  is 
used  by  Wuerdinger  to  designate  the  fact  that  the  cornea,  espec- 
ially the  central  area,  is  made  thinner  and  deprived  of  its  nutrient 
material  by  cocain.  If  such  an  eye  cannot  be  closed,  a  rapid  desic- 
cation takes  place.  It  proves,  therefore,  that  the  cornea  in  this 
condition  is  extraordinarily  inclined  to  absorb  medicinal  fluids,  such 
as  sublimate  solution,  which  have  been  poured  over  it,  and  conse- 
quently it  becomes  still  more  opaque.  To  avoid  cocain  opacities 
it  is  best  to  have  the  eye  closed  after  each  drop  of  solution,  and 
not  to  hold  the  eye  open  longer  than  is  necessary  when  the  opera- 
tion is  going  on.  Milder  degrees  of  cocain  opacities  disappear 
without  a  trace,  and  those  which  remain  are  usuall}'^  caused  by 
cocain  and  sublimate  .together.  As  Nellinger  has  shown,  they 
result  from  the  fact  that  the  sublimate  solution  penetrates  to  the 
anterior  chamber  and  remains  there.  The  part  played  by  cocain  is 
of  importance  only  in  so  far  as  it  encourages  the  penetration  of 
fluid  to  the  anterior  chamber  by  reducing  the  tension  of  the  eye 
and  lowering  the  resisting  power  of  the  protective  endothelium. 

3.  Keratitis  Striata.  —  Another  corrective  proceeding,  the 
bandage,  is  equally  liable  to  produce  corneal  opacities,  particularly 
if  it  is  applied  too  tightly.  These  show  themselves  as  delicate  light 
gray  lines  which  cross  the  cornea  in  all  directions,  so  that  they 
have  the  appearance  of  a  crack   on   the  surface  of  ice.     Probably 


PRESSURE    OPACITY CICATRICIAL   OPACITY.  253 

these  stride  are  due  to  the  formation  of  wrinkles  in  the  cornea.  A 
striate  keratitis  is  most  often  seen  after  a  cataract  operation,  the 
striations  being  perpendicular  to  the  incision  and  passing  with  more 
or  less  divergence  toward  the  center  of  the  cornea,  sometimes  ex- 
tending quite  to  the  opposite  edge. 

Knies  was  the  first  to  explain  striate  keratitis  after  cataract  oper- 
ation as  due  to  wrinkling  of  the  cornea.  Hess  has  recently  tried 
to  prove  that  these  striae  are  wrinkles  of  Descemet's  membrane. 
They  usually  disappear  after  two  or  three  weeks,  but  cases  have 
been  reported  where  they  remain  permanent. 

4.  Pressure  Opacity. — If  the  eye  of  an  animal  is  seized  and  firmly  pressed  between 
the  finger  and  thumb,  the  cornea  becomes  white  and  untransparent.  This  opacity  due  to 
pressure  may  be  observed  in  the  eye  of  man  if  attempt  is  made  to  make  an  incision  in  the 
cornea  with  a  dull  knife  ;  the  cornea  becomes  opaque  al)out  the  point  of  the  knife.  Such 
an  opacity  is  not  due  to  any  anatomical  change,  since  the  transparency  returns  immedi- 
ately when  the  pressure  is  removed.  It  depends,  rather,  as  Kleischl  says,  upon  the  dif- 
ference in  tension  of  individual  fibers ;  those  that  are  the  most  stretched  become  doubly 
refractive,  this  change  from  weaker  to  stronger  refracting  fibers  impairing  the  transparency. 

It  might  be  supposed  that  a  corneal  opacity  resulting  from  increase  of  internal  tension, 
such  as  we  see  in  glaucoma,  might  be  explained  in  the  same  way,  but  investigations  by 
Fuchs  have  shown  that  this  is  not  the  case.  The  very  fact  that  a  glaucomatous  corneal 
opacity  disappears  quickly,  but  not  instantaneously,  negatives  the  similarity.  Moreover, 
there  has  been  detected  as  cause  of  this  glaucomatous  opacity  an  anatomical  change,  which 
Fuchs  calls  "  edema  of  all  the  layers  of  the  cornea  ;  "  the  substantia  propria  has  a  re- 
laxed appearance  instead  of  its  normal  homogeneous  density,  the  nerve  channels  are 
dilated,  and  below  the  epithelium  are  found  droplets  of  fluid.  This  dull  appearance  of 
a  glaucomatous  cornea  is  due  to  these  droplets.  It  is  most  prominent  at  the  center  of  the 
cornea. 

5.  Ribbon-like  opacities  attack  that  portion  of  the  cornea  exposed  beneath  the 
palpebral  fissure.  As  a  rule  this  opacity  begins  in  two  places — at  the  temporal  and  at  the 
nasal  side  of  the  cornea.  Both  opacities  growing  toward  each  other  become  united  at 
the  center  of  the  cornea,  and  then  form  a  broad  band  J  to  j  mm.  wide,  which  gives  the 
name  to  the  disease.  The  opacity  is  of  an  even,  light-gray  color,  the  dots  and  stria?  in 
it  being  detectible  only  by  a  lens.  The  surface  of  the  cornea  is  usually  dull  and  mottled. 
The  disease  attacks  both  eyes  as  a  rule,  and  is  developed  very  slowly  without  any  signs 
of  inflammation  ;  visual  disturbance  is  the  only  complaint  the  patient  makes.  It  is  sup- 
posed that  a  -calcareous  degeneration  of  anterior  layers  of  the  cornea  is  the  essential 
characteristic  of  the  disease.  It  usually  attacks  elderly  persons  whose  eyes  are  otherwise 
sound,  or  others  whose  eyes  have  already  suffered  from  glaucoma  or  iridocyclitis. 

Treatment  can  do  little.  If  there  has  been  glaucoma,  an  iridectomy  may  be  of  ser- 
vice.    In  healthy  eyes  the  attempt  has  been  made  to  curette  the  superficial  opacification. 

6.  Cicatricial  Opacity. — All  corneal  injuries  and  ulcers  pene- 
trating Bowman's  membrane  and  affecting  the  substantia  propria, 
as  well  as  many  a  keratitis  without  ulceration,  in  healing  leave 
behind  an  opacity  which  is  called  either  a  leukoma  or  macula  or 


254  msir4*iiES  of  the  cornea. 

nubecula.  Leukoma  is  an  opacity  tiuit  reflects  x>early  all  the  light 
MMpuigiag  «^>oa  k,  and  therefore  afipears  to  the  observo'  as  a  white 
blolck.  MaoiAa  is  a  less  dense  ofmdty  which  traasmits  a  large 
part  of  the  tniNi^iiig  I^ht,  and  does  not,  therefore,  aqppear  white, 
bi^  ladKT  bl«ish~gTay,  and  b  generally  only  \-isible  whm  the  ex-e 
is  so  t«T«ed  that  ^e  black  papal  fonns  a  bad^round  for  this  area. 
Nobecoln  is  a  tran^arent,  extremely  driicate  opacity,  which  trans- 
ants  nearly  all  the  ini|Mnging  l^ht,  and  can  therefore  be  detected 
oni^  bgf  optkakl  aid  (/.  pS\  Ex-ery  grade  of  transition  firom  len- 
to mdbecnla  iss  of  course,  possible. 

FocBKxhr,  wiwa 

Aey  vcK  sack 

a  4tefoskt£  lead  visk& 


The  patirnt  a^s  the  physician  s  ach-ice,  either  because  of  the 
dfeignrcMCl  produced  by  a  lenkoma.  or  because  <^  a  visual  dis- 
tnifaaace  firom  an  opacit>%  or.  finafy,  bcaMse  of  an  ulcer  which  is 
stSl  left  at  the  scar.  Naturally  enoi^fc.  the  patient  does  not  always 
know  the  reason  of  his  poor  Tisioa;  he  may  not  complain  at  all  of 
weak-sightednes5,  but  of  short-sightedness,  because  he  instincti\-ely 
brii^  the  book  closer  to  tiK  eyes  in  order  to  see  die  print  onder 
the  grcaicsl  possiMe  Txsoal  angie.  It  is  m  fffmd  fimm  krfmr  tvtrj 
0fiAaimmsnfic  cxmmimttitm^  mmd  tifitr  ettrj  tat  mkert  rinui  madty 
is  ftmmd  A»  ii  d^edivt,  mcrwrmitfy  t»  aaamime  Ae  crnmtm  sraBft  /mcml 


The  degree  of  visual  distmbaace  depends  upon  the  position  and 
nature  oi  the  opacity.  An  opacity  near  the  ec^e  of  d»e  TgiapA.  may 
not  of  itseif  a&ct  vision  at  all,  although  the  transparent  portions 
of  the  conea  nsnaDy  lose  their  regular  curvature  after  the  cure  of 
a  large  marginal  nicer,  especially  if  dtere  has  been  p>erforation  with 
adhesion  of  dK  iris;  the  resi^  is  an  irregular  ast^matism  that 
mnst  decidedly  afcct  ttie  irisarf  acnity.  Opacities  lyii^  ahxigclher 
or  in  part  in  front  of  the  pi^jil  canse  dbtnihanoes  c^  various 
degree.  A  sharply  defined,  r-i-MylctLlji  nnliaiisparent  leukoma 
covering  only  part  of  the  pnpi  wonid  have  nocfiect  npoBvisaal 
acuity,  since  ^ktc  is  still  room  at  the  sides  of  tins  kukoana  for  a 
-  of  faHMMMS  rays  to  reach  tibe  retina  under  normal 
Unfortnnaft^.thereisnosachlcidHMna;  so 
sharply  onftfined,  none  is  oomplcfeely  nn- 


CICATRICIAL   OPACITY.  255 

transparent,  and  those  transparent  portions  of  the  cornea  lying 
next  to  it  are  always  irregularly  astigmatic  ;  nevertheless,  a  tolerable 
visual  acuity  may  remain  in  spite  of  a  central  leukoma.  Blotches 
on  the  cornea  are  disturbing  factors,  too,  since  different  parts  of 
these  blotches  may  be  self  luminous  and  may  flood  the  entire 
retina  with  a  diffuse  shimmer  of  light.  The  physician  can  form  a 
general  idea  of  the  amount  of  visual  disturbance  when  he  uses  the 
ophthalmoscope,  the  more  indistinct  the  fundus  appears  to  him,  the 
worse  must  the  outer  world  appear  to  the  patient. 

Treatment. — How  can  such  a  patient  be  benefited  ?  Wecker 
proposed  tattooing  for  the  disfigurement.  This  is  done  by  rapidly 
pricking  the  white  corneal  scar  with  a  bundle  of  needles,  after  which 
a  stick  of  India  ink  is  rubbed  over  the  perforated  corneal  area.  The 
cornea  is  now  washed  off  to  see  whether  the  black  puncture  points 
are  close  enough  together  to  turn  the  white  scar  completely  black. 
If  this  has  not  been  done,  the  pricking  and  the  India  ink  should  be 
repeated,  and  the  whole  process  continued  until  the  desired  result 
is  reached.  It  is  to  be  understood  that  the  cornea  has  been  anes- 
thetized by  cocain  and  that  the  needles,  India  ink,  and  the  fingers 
are  absolutely  aseptic.  In  successful  cases  tattooing  is  said  to  have 
had  a  good  influence  on  vision,  since  the  semitransparent  leukoma 
was  made  quite  impenetrable  to  light. 

There  are  numerous  means  for  overcoming  the  visual  disturb- 
ance. It  must,  first  of  all,  be  determined  whether  any  opacity  pres- 
ent is  really  due  to  a  cicatrix,  or  w  hether  it  depends  upon  the  rem- 
nants of  some  inflammatory  infiltrate ;  in  the  latter  case  the  eye  is 
seen  to  be  somewhat  irritated,  a  condition  ver\'  apt  to  be  detected 
after  a  prolonged  examination.  By  the  presence  of  ciliary  injection 
it  is  seen,  moreover,  that  the  clouded  area  shows  fine  irregularities, 
that  the  opacity  is  not  ver\-  sharply  outlined,  but  is  gradually  lost 
in  healthy  tissue,  and  finally — this  is  the  most  trustworthy  sign — 
that  there  are  still  some  blood-vessels  running  to  the  cloudy  area. 
When  there  is  even  a  suspicion  of  an  inflammatory  infiltrate,  the 
attempt  should  be  made  to  clear  it  up  by  continued  massage  with 
yellow  ointment.  It  may  be  noticed  that  in  very  young  children 
genuine  scar-tissue  can  be  made  noticeably  brighter  after  months 
or  years  of  treatment,  so  that  the  scar  resembles  true  corneal  tissue 
very  closely.  If  this  last  stage  has  been  reached,  the  attempt  should 
be  made  to  improve  vision  by  concave  glasses.  This  is  sometimes 
successful,  even  if  there  is  no  myopia,  because  a  concave  lens  de- 


256  DISEASBS  €»  HUE.  CORXEA. 

mauds  an  efibrt  of  accommodation,  and  consequently,  as  tiie  pupil 
contracts,  scene  of  the  diffuse  light  is  shut  off.  We  have,  finally, 
various  operathre  procedures,  such  as  iridectomy  and  the  substitu- 
tion of  transparent  cornea  in  the  place  of  tissue  partially  or  entirely 
opaque — itrtUopUufy.  An  optical  iridectomy  promises  success  only 
vdbcB  sotne  portion  of  the  cornea  is  transparent,  behind  which  an 
artificial  p<^m1  may  be  made.  It  is  not  always  easy  to  determine 
this  exactly,  since  delicate  opjacities  cannot  be  easily  detected 
against  the  comparatively  bright  background  of  the  iris,  but  occa- 
aioB^ijra  good  conclusion  is  reached  by  dilating  the  natural  pupil 
and  apph-ing  proper  diaphragms,  which  may  show  what  improve- 
ment to  the  visual  acuitv*  may  be  expected  from  an  artificial  pupil. 
If  there  is  any  choice,  an  iridectomy  should  be  made  downward 
and  inward,  because  the  visual  axis  passes  through  the  cornea 
rwhat  downward  and  inward  from  its  center  (/.  S^). 


\  Aoe  »  «  rhirr  ttii  4at%  — t  hipyai  «Abb,  hMwac* — I  fieier  to  {iaoe  die 
■pfl  rfnve^liecMHeAeapperfiiai^adkedMactiiiMl  fpB  liyrcr  — alW, 
to  csTflBKtiBoes.  Aa  opticii  vidcctaM^  fliMSit  jlvjfjfs  taiBK  oat  lamger  and 
■Hie  pexipfaexal  i&aa  the  mbj^bob  iateadei.  Sefcorirr  kai  Atwfcwe  prapMed  to  per- 
iaam.  iait»am%  m  place  of  aidotuaiy.  Tke  p^al  Ans  aade  is  &e  a  dk,  ariack  ^t%  x 
mmA.  iieaer  VHaal  acaitr,  eiprriaBy  ia  aear  vimb,  ikiB  4oes  iridrrtnaiy.  Whether  this 
kaer  wiB  be  ^yhced  by  SAoeieg's  ■eAod  ia  atii  a  faniJM 

The  insertion  of  transparent  cornea  is  as  yet  an  operation  of  the 
future.  No  method  has  hitherto  been  devised  by  which  opaque 
cornea  can  be  replaced  by  transparent  tissue.  The  operation  itself 
is  an  easy  one,  and  union  takes  place  without  any  difiiculty,  but  the 
transplanted  cornea  is  not  able  to  retain  its  tran^nrency  under  its 
new  conditions;  it  becomes  opaque,  and  the  purpose  of  the  opera- 
tion is  turned  to  naught.  V.  Hippel  has  achieved  success  in  cor- 
neal transplantation  b>'  making  a  section  of  the  cornea  with  a  tre- 
phine only  down  to  Descemet's  membrane,  and  in  this  excised 
aica  a  corre^>oodM^  bat  of  a  rabbit's  cornea  was  made  to  heal ; 
KfliuBt  also  has  had  success  in  one  case.  It  is  evident,  however,  that 
even  if  the  method  of  v.  Hippel  should  become  common  property, 
k  vooki  be  oaly  a  subdiv»aoa  of  genuine  keratoplasty,  the  aim  of 
vbkli  Aorfd  be  to  excise  the  cornea  in  its  entire  thickness  and  to 
repiace  it  by  living  animal  tissue. 


STAPHYLOMA    CORNE.t:.  257 

IV.  PROTRUSIONS  OF  THE  CORNEA. 

I.  Staphyloma  Corneae  is  a  corneal  scar  which, with  the  adherent 
iris,  bulges  outward.  It  may  be  partial  or  total,  according  to 
whether  the  cornea,  in  part  or  as  a  whole,  is  changed  into  a  pro- 
truding scar  or  cicatrix. 

The  cause  of  this  condition  has  been  already  mentioned  on  //. 
22^  and  226.  It  need  only  be  explained  here  how  it  happens  that 
a  corneal  scar  does  not  contract,  as  do  others,  but,  on  the  contran,-, 
protrudes  more  and  more,  until  it  resembles  a  growing  tumor.  The 
adhesion  of  the  iris  to  the  cicatrizing  cornea  produces  traction  on 
the  ciliary  body,  that  vascular  and  nervous  part  of  the  inner  tunic 
of  the  eye  by  which  the  aqueous  humor  is  secreted.  Irritation  of 
the  ciliary  body — so  it  is  assumed — increases  secretion  ;  the  inter- 
nal pressure  of  the  eye  is  thereby  raised.  This  heightened  tension 
pushes  the  scar  forward  with  greater  force ;  the  ciliary  body  is 
thereby  still  more  dragged  upon,  with  the  consequence  of  shutting 
up  the  circulus  vitiosus. 

The  protrusion  may  come  to  a  standstill,  or  it  may  continue  to 
increase  until  the  staphyloma  ruptures,  when  the  aqueous  escapes 
and  the  staphyloma  collapses.  This  improvement  is,  however,  of 
only  short  duration.  The  perforation  closes  again,  the  space  be- 
tween lens  and  iris  (the  posterior  chamber)  again  fills  up.  and  the 
staphyloma  soon  assumes  its  abnormal  size.  This  process  may  be 
repeated  again  and  again,  until  finally  the  perforation  becomes  the 
entering  gateway  for  germs  which  destroy  the  eye  by  suppuration 
(panophthalmitis). 

Increased  tension  resulting  from  long-continued  mecbanical  iiritatioo  erf  the  cilianr 
body  is  an  assumption  but  not  an  undisputed  fact.  This  increased  tension,  in  many  a 
staphyloma  at  least,  may  be  explained  in  a  different  way.  If  the  staphyloma  is  a  total 
one,  the  anterior  chamber  is  compietriy  obliterated,  and  the  filtration  angle,  that  physio- 
logical di^-harge  pipe  oi  the  aqueovs  iMMnor,  is  closed.  Increased  ten.sion  would  be  due, 
therefore,  not  to  an  increase  in  secretion  but  to  a  hindrance  to  the  escape  of  the  aqueous. 

The  diagnosis  of  a  staphyloma  is  easy ;  in  the  partial  form  a 
spherical  protrusion  occupies  a  portion,  and.  as  a  rule,  the  lower 
portion,  of  the  transparent  cornea.  The  color  of  this  untransparent 
area  differs  according  to  the  thickness  or  thinness  of  the  scar-tissue, 
and  consequently  the  adherent  iris  is  seen  through  it  with  more  or 
less  distinctness.  The  color  of  the  scar-tissue  itself  is  white  or  a 
dull  yellow,  that  of  the  pigment  of  the  iris  is  black ;  consequently, 
J7 


258  DISEASES    OF    THE    CORNEA. 

a  staphyloma  may  be  either  white  or  yellow,  bluish-white  or  bluish- 
black.  There  may  be  a  bit  of  red  mixed  with  the  other  color,  since 
blood-vessels  from  the  conjunctiva  may  be  drawn  into  the  scar- 
tissue.  A  total  staphyloma  {Fig.  pi)  has  usually  a  spherical,  but 
occasionally  an  irregular  shape.  As  a  rule,  the  external  edge  of 
the  cornea  is  not  destroyed  by  the  suppurative  process  ;  it  remains 
comparatively  transparent,  so  that  the  iris  can  be  seen  through  it. 
When  the  tension  becomes  raised,  this  border  between  cornea  and 
sclera  is  gradually  destroyed, 

A  patient  with  a  staphyloma  is  a  great  sufferer.  Disfigurement 
is  by  no  means  his  worst  misfortune.  This  is  of  less  consequence 
to  him  than  the  impairment  of  the  visual  acuity.  Even  a  partial 
staphyloma,  which  leaves  the  pupil  to  a  certain  extent  free,  is 
accompanied  by  most  pronounced  "  irregular  astigmatism,"  which 
on  its  own  account  impairs  the  visual  acuity.  In  a  total  staphyl- 
oma vision  is  quite  out  of  the  question  ;  the 
eye  can  distinguish  only  light  from  darkness. 
If  the  other  eye  is  uninjured,  many  a  patient 
might  tolerate  this  unfortunate  condition,  but 
he  has  no  peace ;  at  every  movement  of  the 
lid  and  of  the  eyes  the  protruding  knob  is  irri- 
tated by  the  edges  of  the  lids,  while  it  may,  on 
its  part,  prevent  them  from  closing  at  all.  This 
Fig.  91.-T0TAL  staphy-     ^11  rcsults  in  a  painful  condition  of  inflamma- 

LOMA.    {After  Stchel.)  " 

tion,  and  if  the  lids  cannot  close,  the  unprotected 
staphyloma  may  shrivel  up  or  ulcerate.  The  deeper  parts  of  the  eye 
then  become  involved  (secondary  glaucoma),  which  will  lead  to  the 
acute  pain  of  ciliary  neuralgia  and  to  atrophy  of  the  optic  nerve. 

Treatment  can  be  successful  only  when  it  is  begun  early  enough, 
that  is,  at  a  time  when  the  condition  is  that  of  a  simple  prolapsus  of 
the  iris.  By  abscission  of  this  prolapse,  by  eserin,  by  rest,  and  a 
long-continued  pressure  bandage,  it  is  sometimes  possible  to  pro- 
duce a  flat  and  firm  cicatrix,  and  in  the  end  to  keep  the  eye  per- 
manently at  rest. 

Abscission  of  a  prolapsed  iris  cannot  be  well  performed  with  a  stroke  of  the  scissors, 
since  the  prolapsed  nodule  is  almost  sure  to  escape  from  between  their  blades.  The 
operation  is  much  better  performed  with  Graefe's  Cataract  Knife  (/>>.  126)  by  piercing 
the  base  of  the  prolapsus  at  its  center  and  cutting  outward  in  the  plane  of  the  base.  The 
two  flaps  thus  exposed  are  then  seized  with  toothed  forceps  and  abscised  completely 
with  either  knife  or  scissors. 


KERATOCONUS. 


259 


If  this  first  stage  is  already  passed,  so  that  the  iris  has  become 
incarcerated  in  the  cicatrix,  it  is  best  to  reduce  the  internal  pressure 
by  an  iridectomy,  and  in  this  way  to  encourage  the  scar  to  flatten 
out.  Of  course,  the  iridectomy  should  be  placed  wherever  an  arti- 
ficial pupil  would  seem  to  be  most  advantageous  for  vision.  If  the 
staphyloma  increases  in  spite  of  the  iridectomy  and  of  long-contin- 
ued bandaging,  the  staphyloma  itself  must  be  cut  off.  If  the  sta- 
phyloma is  total,  there  will  be  left  a  rather  large  wound  in  which 
the  lens  is  exposed,  but  since  it  is  already  opaque,  it  is  best  in  any 
case  to  remove  it  at  once.  The  gaping  wound  must  be  closed  by 
two  or  three  stitches,  placing  them  either  through  the  edges  of  the 
wound  or  through  the  conjunctiva  after  it  has  been  freed  from  its 
adhesion  to  the  eyeball,  so 
that  it  can  be  drawn  over  the 
wound  by  these  sutures.  This 
operation  does  not  attempt  to 
restore  any  visual  power,  but 
only  to  form  a  suitable  stump 
for  a  glass  eye. 


Fig.  92. — Khratoconus.     (A/ter  A.  v.  Crae/e.) 


If  keratoplasty  is  ever  successful  in 
the  future,  a  new  transparent  cornea 
will,  of  course,  be  used  in  the  place  of 
the  excised  staphyloma. 

If  the  staphyloma  is  not  to 
be  treated  until  the  eye  is  com- 
pletely blind  by  heightened 
tension  and  optic  nerve  atro- 
phy, enucleation  must  be  considered,  and  the  decision  should  not  be 
long  delayed  if  chronic  inflammation  of  the  staphylomatous  eye 
threatens  the  remaining  one  with  sympathetic  inflammation. 

2.  Keratoconus  {Fig.  p2)  is  a  protrusion  of  the  cornea  in  the  form 
of  a  blunt  cone.  The  cornea  is  clear,  the  iris  unaffected.  The 
rounded  point  of  the  cone  lies  at  about  the  middle  of  the  cornea, 
and  is  only  one-third  as  thick  (o.j  /n/n.)  as  the  normal  corneal  apex 
(o.p  w///.).  The  sides  of  the  cone  are  somewhat  thicker  than  the 
periphery  of  a  normal  cornea  (/./  mm.). 

If  the  figure  on  a  keratoscope  {.p.  gy)  is  thrown  upon  the  apex 
of  a  conical  cornea,  the  image  reflected  from  it  is  very  small,  but 
grows  larger  and  larger  as  the  reflection  is  made  from  the  points 
lying  further  and  further  away  from  the  apex  toward  the  periphery. 


26o  DISEASES    OF    THE    CORNEA. 

In  this  way  v.  Graefe  was  able  to  estimate  in  one  case  that  the 
center  of  the  cornea  had  the  radius  of  curvature  of  a  pea,  while 
the  edges  of  the  cornea  had  the  radius  of  curvature  of  a  small 
potato.  It  is  easy  to  see  that  such  a  cornea  cannot  throw  distinct 
images  upon  the  retina,  consequently  these  patients  have  very  poor 
vision  :  V  =  .-,  for  example.  Since  objects  lying  toward  the  peri- 
phery are  seen  very  indistinctly,  the  patient  has  great  difficulty  in 
finding  his  way  in  a  strange  place.  The  greatest  complaint  the  pa- 
tient has  to  make  is  that  of  multiple  vision — polyopia  monocularis — 
and  irritation,  which  is  probably  due  to  the  unavoidable  dazzling. 

To  recognize  a  completely  developed  conical  cornea  it  is  only 
necessary  to  look  at  the  patient  from  one  side.  The  sugar-loaf  ap- 
pearance of  the  transparent  protruding  cornea  (/v^.  p^)  explains  the 
whole  matter.  At  the  beginning  of  the  condition,  however,  a  mod- 
erate protrusion  may  be  easily  overlooked,  but  a  careful  use  of  kera- 
toscopy  and  of  the  ophthalmometer  will  prevent  any  error.  In  the 
last  stage  the  diagnosis  may  be  difficult,  because  the  apex  of  the 
cone  becomes  cloudy  at  last  and  may  simulate  a  healed  ulcer. 

The  morphology  of  conical  cornea  is  obscure.  We  know  that  it  occurs  in  young  per- 
sons between  the  fifteenth  and  twenty-fifth  years  without  any  evidence  of  inflammation, 
that  its  advance  is  extremely  slow,  although  it  may  quite  suddenly  spring  into  activity, 
that  the  development  may  come  to  a  standstill  in  any  stage,  and  that  perforation  does  not 
occur  even  in  the  most  pronounced  type.  It  is  supposed  that  the  cause  is  an  undue  thin- 
ness of  the  apex  of  the  cornea.  Whether  the  apex  of  the  cornea  was  too  thin  from  birth, 
and  why  the  anterior  chamber  yields  to  the  internal  pressure  only  in  later  youth,  are  still 
unanswered  questions.  His  tried  to  solve  this  problem.  He  scratched  off  the  endothe- 
lium at  the  apex  of  a  guinea-pig's  cornea,  and  found  that  the  posterior  layers  of  the  cor- 
nea grew  cloudy,  and  that  the  corneal  apex  protruded  at  the  same  time.  The  cloudiness 
disappeared,  but  the  protrusion  remained.  It  is  probable  that  in  man  some  disease  of 
the  endothelium  has  undermined  the  resistive  power  of  the  apex  of  the  cornea. 

Treatment. — Vision  may  sometimes  be  improved  by  very  strong 
concave  lenses,  because  the  greatest  optical  effect  is  produced  at  the 
apex  of  the  cornea.  The  hyperbolic  glasses  devised  by  Raehlmann 
are  of  still  greater  service;  rays  which  pass  through  the  center  of 
such  a  glass  diverge  rapidly,  while  those  passing  through  the  peri- 
phery diverge  slowly,  and  they  therefore  neutralize  the  uneven  con- 
vergence of  the  rays  produced  by  the  different  sections  of  the  cor- 
nea. The  great  disadvantage  is  that  such  a  hyperbolic  glass  must 
be  exactly  centered  with  the  hyperbolic  cornea,  but  as  soon  as  a 
patient  turns  his  eye  behind  the  glass  the  least  trifle  to  one  side, 
the  neutralizing  effect  ceases,  and  his  condition  is  worse  than  be- 


KERATOGLOBUS KERATEKTASIA TUMORS.  26  I 

fore.  It  would  still  seem,  therefore,  that  the  best  results  are 
reached  by  an  operation,  destroying  the  apex  of  the  cone  by  the 
knife  or  the  cautery,  and  leaving  in  its  place  a  more  resistive  scar. 
It  must  be  confessed  that  such  a  scar  is  untransparent,  and  that  a 
high  price  has  been  paid  for  the  flattening  of  the  entire  cornea  thus 
obtained,  and  the  operation  must,  therefore,  be  supplemented  by  an 
optical  iridectomy. 

I  have  proposed  to  treat  conical  cornea  with  a  "contact  glass,"  that  is,  with  a  glass 
ground  so  as  to  have  the  form  of  the  normal  anterior  segment  of  the  eye,  this  glass  to  be 
laid  directly  u]X)n  the  affected  eye,  the  space  between  glass  and  cornea  being  tilled  with 
some  aseptic  fluid  of  the  same  refractive  index  as  that  of  the  cornea.  If  this  were  done, 
the  influence  of  the  conical  cornea  upon  the  path  of  the  luminous  rays  would  be  destroyed. 
Unfortunately,  I  have  found  no  case  exactly  suited  for  the  application  of  such  a  contact 
glass,  but  the  improved  visual  acuity  in  proper  cases  of  irregular  corneal  astigmatism  has 
been  suqjrising. 

Keratoglobus  is  the  name  given  to  a  second  kind  of  protrusion  of  a  transparent 
cornea.  I  have  seen  two  cases  of  this  unusual  condition  which  resembled  each  other 
very  much.  In  the  first  case  I  noted  the  following  characteristics  :  Both  coriieae  and  irides 
appeared  decidedly  enlarged ;  a  measurement  of  the  horizontal  diameter  of  the  cornea 
was  easily  made,  since  the  cornei  was  sharply  outlined  from  the  sclera ;  in  the  right  eye 
this  was  about  75  /«;«.,  in  the  left  eye  a  trifle  smaller.  Both  cornete  were  absolutely 
clear.  The  anterior  chamber  in  each  eye  was  veiy  deep,  perhaps  about  8  to  10  mm. 
If  the  eye  was  looked  at  from  the  temporal  side,  it  gave  the  impression  of  a  glass  hemi- 
sphere laid  with  its  surface  upon  the  iris  and  protruding  nearly  to  the  front  of  the  cornea 
or  to  its  apex,  but  at  the  periphery  not  approaching  quite  so  closely.  The  iris  was  quite 
smooth  and  lay  somewhat  behind  the  plane  of  the  sclero-corneal  border ;  it  trembled 
when  the  eye  was  moved.  The  eyes  were  hyperopic,  visual  acuity,  fundus,  and  tension 
being  normal ;  the  patient  denied  any  possibility  of  earlier  disease  (glaucoma).  Both 
cases  confirmed  the  view  of  Horner,  W.  v.  Muralt,  and  L.  Pflueger,  that  keratoglobus 
is  an  anomaly  having  nothing  in  common  with  infantile  glaucoma  [q.  v. ). 

Keratektasia  is  the  name  given  to  a  protrusion  of  an  opaque,  that  is,  cicatrized, 
cornea.  It  has  this  in  common  with  keratoconus  and  keratoglobus  that  the  iris  remains 
unaffected  ;  keratektasia  is  the  result  of  a  corneal  ulcer  which  has  not  ended  in  perfora- 
tion but  rather  in  a  thinning  of  the  cornea ;  or  it  is  the  result  of  pannus  and  other  "  non- 
suppurative "  corneal  diseases. 

Tumors  arising  in  the  cornea  itself  are  extraordinarily  infrequent. 
New  growths  which  arise  at  the  lim.bus  conjunctivae  and  attack  the 
cornea  afterward  are  comparatively  common ;  they  are  discussed 
on  p.  218. 


262  DISEASES   OF   THE    SCLERA, 


DISEASES  OF  THE  SCLERA. 

I.  INFLAMMATIONS. 

Episcleritis. — Inflammations  of  the  sclera  are  usually  secondary 
to  those  of  the  cornea  or  ciliary  body.  They  are  of  small  impor- 
tance compared  to  the  principal  disease.  Idiopathic  inflammation 
of  the  sclera  is  rare.  It  is  a  localized  disease  evidenced  by  a  flat- 
tish  nodule  about  the  size  of  a  lentil  lying  j  to  ^  mm.  from  the 
edge  of  the  cornea.  Its  color  is  yellowish-red  at  the  center,  bluish- 
red  at  and  around  the  edge.  Examined  carefully  with  a  good  lens, 
the  conjunctival  cover  of  this  nodule  appears  of  a  light  red  color. 
If  the  conjunctival  blood-vessels  are  kept  empty  by  gentle  pressure 
by  the  finger,  the  bluish-red  scleral  vessels  are  seen  more  clearly. 
If  now  these  latter  vessels  are  kept  empty  by  a  somewhat  stronger 
pressure,  it  is  seen  that  the  nodule  is  made  up  of  minute  vesicles  of 
a  yellowish  color.  This  pressure  causes  moderate  pain.  The  con- 
dition may  last  some  weeks  with  only  a  few  symptoms;  the  inflam- 
matory redness  then  gradually  fades  away,  the  nodule  flattens  out 
and  finally  disappears,  leaving  a  slate-gray  discoloration.  But  the 
disease  has  by  no  means  run  its  course ;  after  a  longer  or  shorter 
interval — weeks,  months,  or  years — a  new  nodule  is  formed  near 
the  site  of  the  earlier  one,  and  this  leaves  in  its  turn  another  slate- 
gray  blotch.  So  it  goes  on,  until  after  years  the  entire  strip  of 
sclera  between  the  edge  of  the  cornea  and  the  insertions  of  the 
tendons  of  the  four  recti  muscles  is  occupied  by  blotches  ;  hence 
the  name  episcleritis  migrans.  Occasionally  the  disease  is  not  re- 
stricted to  the  sclera,  but  attacks  the  cornea  also.  The  condition 
is  then  that  of  keratitis  scleroticans,  described  on  /.  2.^6.  In  other 
cases  the  disease  passes  inward,  attacks  the  ciliary  body  and  the 
anterior  part  of  the  choroid,  and  is  then  called  sclero-choroiditis  ante- 
rior (/.  2g6).  It  is  by  no  means  certain,  however,  whether  this  last 
form  arises  originally  in  the  sclera  or  in  the  choroid  or  ciliary  body. 

The  diagnosis  of  episcleritis  is  easy  if  any  adjacent  slate-gray 
blotches  aid  in  explaining  the  nodule  present  at  the  time.  If  this 
is  not  the  case,  it  may  be  confused  with  a  conjunctival  phlyctenule. 
To  avoid  this,  it  must  be  remembered  that  a  phlyctenule  is  a  vesicle 
of  the  conjunctiva  filled  with  cellular  debris,  and  that  therefore  its 
center  cannot  be  covered  with  the  network  of  vessels  which  is  seen 
over  the  episcleritic  nodule.     If  a  phlyctenule  has  changed  to  a 


ECTASIA.  263 

shallow  ulcer  the  diagnosis  is  very  easy,  siiKre  this  canaot  ^appfn 
in  episcleritis  ;  the  nodule  is  surrounded  trith  a  bluish-red  area  of 
inflammation,  while  in  a  phlyctenule  the  side  turned  toward  the 
cornea  is  comparatively  free  from  blood-vesseis.  In  doubtful  cases 
the  further  course  of  the  disease  will  settle  the  question — a  jAlyc- 
tenule  lasts  but  a  short  time,  episcleritis  a  long  time. 

The  nature  of  the  disease  is  obscure ;  it  is  supposed  that  it  resahs 
from  some  general  dyscrasia,  probably  from  gout,  rheumatism, 
sv-philis,  or  tuberculosis.  In  any  case  of  episderitis,  therefore, 
these  four  diseases  must  always  be  searched  for  and  the  treatment 
directed  accordingly. 

The  diagnosis  is  ^vorable,  since  the  disease  causes  few  SA-m|>toms 
and  Iittl^injur\-  to  the  e\'e,  however  long  it  may  last ;  the  disfig- 
urement of  the  grayish  blotches  is  of  no  significance. 

Treatment  must  be  general.  If  gout  is  detected,  dietetic  rules 
must  be  enforced.  If  the  joints  are  swollen,  salicylate  of  lithia  or 
soda  may  be  helpful.  In  s\'philis  and  tuberculosis  the  well-known 
rules  of  treatment  are  to  be  ^plied.  If  no  one  of  these  four  dis- 
eases can  be  detected,  an  impressiN'e  diaphoresis  may  at  least  be 
tried  ;  in  local  treatm^it  all  stimulants  must  be  avoided  ;  only  in  a 
ver\'  chronic  condition  may^  a  careful  trial  of  massage  wnth  yellow 
ointment  be  made.  In  a  fresh  attack  moist  heat  and  a  pressure 
bandage  will  accomplish  as  much  as  anything.  The  two  may  be 
happily  combined  by  appl\*ing  every  night  a  moist  and  warm  band- 
age beneath  gutta  percha  paper.  Atropin  is  indicated  only  when 
the  choroid  is  involved  (sclero-choroiditis  anterior).  If  the  pre- 
sumption is  warranted  that  the  nodule  is  tubercular,  the  conjunctiva 
may  be  incised,  the  granulaf  tissue  curetted,  and  iodoform  applied. 

2.  PROTRUSIONS. 
Ectasia. — The  shape  of  the  eyeball  may  be  changed  in  many 
ways,  and  the  sclera  must  necessarily  pxartake  of  the  alteration,  but 
the  stretching  of  the  sclera  in  infantile  glaucoma  and  myopia,  or 
its  collapse  in  phthisis  bulbi,  are  not  really  diseases  of  the  sclera, 
since  the  role  it  plays  in  such  changes  is  merely  subordinate. 
Strictly  speaking,  the  same  is  true  of  any  ectasise  of  the  sclera, 
since  they  are  but  consequences  of  some  disease  of  the  middle  coat 
of  the  eye,  the  uvea.  Nevertheless,  they  deser\'e  mention  here, 
since  scleral  changes,  in  certain  stages  of  the  disease,  at  least,  are 
those  most  remarked  bv  the  obser\'er. 


264 


DISEASES    OF    THE   SCLERA. 


Ectasia  of  a  portion  of  the  sclera  is  situated  usually  near  the 
cornea,  less  often  at  the  equator.  The  protruding  sclera  is  thinned, 
the  black  uveal  pigment  is  seen  through  it,  and  gives  to  the  pro- 
trusion a  bluish-gray  or  dark  brown,  or  even  a  black  color.'  The 
thinness  of  the  protruded  sclera  is  characteristic  of  ectasia  ;  it  may 
be  detected  by  the  probe,  since  its  wall  yields  to  the  pressure  of 
the  end  of  the  probe,  but  springs  back  into  its  old  place  again  as 
soon  as  the  probe  is  removed.  If  the  protrusion  is  due  to  any  new 
growth,  such  as  a  melanosarcoma  of  the  choroid,  the  pressure  of 
the  sound  will  reveal  a  firm,  unyielding  body  beneath.  Transillumi- 
nation is  another  test  which  may  be  used  for  the  same  purpose ; 
if  light  from  the  ophthalmoscope  is  reflected 
through  the  dilated  pupil  toward  the  ectasia, 
the  thinned  area  of  the  sclera  will  be  seen  to 
become  luminous.  If  the  test  is  made  im- 
practicable by  some  corneal  scar  or  by  a 
contracted  pupil,  the  area  on  the  sclera  op- 
posite to  the  ectasia  may  be  illuminated  as 
intensely  as  possible  by  a  convex  lens  ;  the 
thinned  sclera  will  then  transmit  some  of  the 
light  which  has  penetrated  to  the  interior  of 
the  eye.  Such  tests  must,  of  course,  be  per- 
formed in  the  dark  room.  The  result  is 
negative  if  the  protrusion  is  due  to  a  tumor. 


Fig.  g3. — Ectasia  Ciliaris. 
(After  Pagenstecher  and 
Genth  ) 

The  entire  ciliary  region 
bulges  forward,  particularly 
at  the  outer  (temporal)  side. 
The  ciliary  body  is  there- 
fore decidedly  elongated. 
There  have  been  retinal 
hemorrhages  at  the  back  of 
the  eye. 


An  ectasia    is    named,  according  to   its  location,  infer- 
calaia,  ciliaris  {^Fig.  gj),  or  equatorialis.     The  two  latter 
terms   explain    themselves.     Ectasia   intercalata  implies  a 
protrusion  in  the  region  of  the  ligamentum  pectinatum,  that  is,  in  the  tissue  intercalated  ^ 


^  For  this  reason  ectasiae  of  the  sclera  are  also  called  "  staphylomata."  The  term 
staphyloma  is,  as  Saemisch  long  ago  lamented,  used  in  ophthalmology  for  many  condi- 
tions that  have  no  genuine  relationship  to  each  other.  A  "  corneal  staphyloma  "  is  a 
protruded  corneal  cicatrix  subsequent  to  perforation  and  prolapse  of  the  iris  ;  ' '  anterior 
scleral  staphyloma"  is  a  protrusion  of  thinned  sclera;  "staphyloma  posticum  "  is  an 
aperture  in  the  choroid,  through  which  exposed  sclera  is  visible  with  the  ophthalmoscojie. 
It  is  advisable,  therefore,  especially  in  protrusions  of  anterior  portions  of  the  sclera,  to 
replace  .staphyloma  by  ectasia.  This  indicates  at  once  that  ectasia  corneje  and  ectasia 
sclerse  are  related  conditions,  and  are  both  protrusions  of  a  thinned  but  not  perforated 
external  coat  of  the  eyeball. 

^  Schiess-Gemuseus,  who  first  used  the  expression  "intercalary  staphyloma,"  implied 
by  it  a  protrusion  effected  through  the  tissue,  '■  intercalated  "  between  the  outer  and  inner 
coats  of  the  eyeball.     The  term  is  now  used  in  the  sense  given  above. 


WOUNDS — NEW    GROWTHS.  265 

between  iris  and  ciliary  body.  Ectasia  intercalata  may  be  multiple,  in  which  case  there  is 
a  row  of  them  encircling  the  cornea  parallel  to  its  edge,  having  somewhat  the  appearance 
of  the  colon  in  the  intestines — ectasia  intercalata  annularis. 

Treatment  has  less  to  do  with  the  ectasia  itself  than  with  the 
causative  disease  of  the  choroid,  or  with  the  condition  producing 
the  increase  in  tension. 

3.  WOUNDS. 

Wounds  of  the  sclera,  without  involvement  and  prolapse  of  the 
iris,  choroid,  and  vitreous,  are  scarcely  possible.  The  scleral  wound 
becomes  therefore  subordinate,  in  proportion  to  the  accompanying 
injuries  to  the  eyeball  (see  the  section  on  "  Injuries  of  the  Eyeball  "). 
If  a  recent  wound  of  the  sclera  without  injury  to  deeper  parts 
should  happen  to  present  itself  for  treatment,  the  prognosis  may 
be  given  as  favorable,  since  the  sclera  shows  little  tendency  to 
resent  an  injury  or  to  become  inflamed.  Healing  is  usually  prompt 
and  complete. 

Treatment  is  that  of  wounds  in  general:  disinfection,  closure 
of  the  wound,  bandage.  If  the  edges  of  the  wound  are  well  ap- 
proximated, nothing  more  is  necessary.  If  the  wound  gapes,  a 
conjunctival  or  perhaps  a  scleral  suture  must  be  taken. 

4.  NEW  GROWTHS. 
Tumors  of  the  sclera  arise  very  rarely  from  that  tissue  itself;   they  are  mostly  tumors 
of  the  limbus  of  the  conjunctiva  (/.  21S)  or  of  the  deeper  tissue,  which  have  involved 
the  sclera  later  in  their  growth.     Calcification  of  the  sclera  is  not  unusual  in  the  eyes  of 
old  persons  or  in  atrophic  eyes. 


DISEASES  OF   THE   MIDDLE    TUNIC    OF    THE    EYE 

(^Tunica  media,    Tunica  uvea). 

I.  ANATOMICAL  INTRODUCTION. 

The  middle  tunic  of  the  eye  is  not  a  completely  enveloping  membrane.  Anteriorly 
there  is  an  aperture,  the  pupil,  through  which  luminous  rays  enter,  and  posteriorly 
another  opening  for  the  optic  nerve.      This  tunic  is  divided  into  three  parts  : — 

( /)    The  iris. 

{2)    The  ciliary  body,  and 

(j)    The  choroid. 

Iris. — With  a  good  lens  it  may  be  seen  that  the  anterior  surface  of  the  iris  is  by  no 
means  flat.  Rather  is  it  a  "  relief"  of  mountain,  valley,  ravine,  and  crevasse.  The  most 
prominent  formation  is  a  circular  eminence  about  /  mvt.  from  the  pupil ;  this  indicates 


266 


DISEASES   OF  THE   MIDDLE   TUNIC   OF   THE    EYE. 


the  cirailus  arteriosus  iridis  minor.  The  minute  strand  between  the  small  circle  and 
the  pupil  is  called  the  pupillary  portion,  the  entire  remainder  the  ciliary  portion.  At  the 
pupillary  edge  there  is  a  brown  or  black  band  of  pigment,  which,  when  the  pupil  is  con- 
tracted, lies  in  folds  like  the  ruff  of  a  shirt,  but  when  the  pupil  is  dilated  almost  entirely 
disappears ;  this  band  belongs  to  the  most  posterior,  black-pigmented  layer  of  the  iris 
{Fig.  g4)  and  is  called  "pars  iridica  retinas,"  because  it  belongs  morphologically  to  the 
retina.  Outward  from  the  small  circle  the  iris  passes  in  a  double  curve  toward  the  cili- 
ary edge.  In  the  peripheral  portion  of  the  iris  there  are  to  be  seen  circular  depressions 
concentric  to  the  pupil ;  these  are  the  folds  into  which  the  iris  is  drawn  when  the  pupil 
becomes  dilated.  The  iris  apjjears  to  be  somewhat  smaller  on  the  nasal  than  on  the  tem- 
poral side  ;  in  other  words,  the  pupil  is  eccentric.     Its  size  varies  noticeably,  owing  to 


^BrUck^  mMiseU 


0riicu2uJ  ciliarir. 


Fig.  94.— Ciliary  Body  op  a  Hvpbropic  Evb.    {A/ltr  ltvam«ff.) 


the  action  of  two  unstriated  muscles,  one  being  known  as  the  sphinctfr pupilltr  supplied 
by  the  oculomotor  nerve,  the  other  the  dilatator  pupilhr,  supplied  by  the  sympathetic. 

The  sphincter  is  a  muscle  about  /  mm.  broad  and  o.i  to  o.sj  mm.  thick  {fig.  ./, /. 
^).  It  lies  close  to  the  pupil  and  at  the  posterior  surface  of  the  iris.  The  dilatator  is 
a  single  layer  of  unstriated  muscular  fibers  arising  from  the  sphincter  to  pass  spoke-like  to 
the  ciliar)'  edge  ;  the  fibers  are  clo.se  to  the  pigment-layer  of  the  iris.  The  muscular 
nature  of  these  fibers  has  been  hitherto  disputed — improj>erly,  I  think,  for  in  the  cadaver, 
where  the  sphincter  is  paralyzed,  and  where  a  purely  elastic  dilatator  would  be  as  active 
after  as  before  death,  the  pupil  is  of  only  moderate  width,  about  4  mm.  in  diameter; 
while  in  the  living  body  we  can,  by  paralyzing  the  sphincter  with  atropin  and  simulta- 
neously stimulating  the  dilatator  with  cocain,  produce  a  pupil  having  a  diameter  of  g  to 
10  mm. 

Apart  from  the  double  layer  of  pigment  {^Fig.  9/)  at  the  back  of  the  iris  and  sphincter 
there  is  no  other  stratified  formation  of  the  iris  discoverable.      It  is  somewhat  schematic, 


CILIARY    BODY — BLOOD-VESSELS    IN   THE   UVEAL  TRACT.         267 

therefore,  to  speak  of  a  "vascular  layer."  The  vessels  are  very  numerous,  radiate,  and 
are  provided  with  extraordinarily  thick  walls,  obviously  intended  to  prevent  them  from 
losing  their  lumen  when  stretched  by  the  tension  of  the  iris  The  iris  is  luxuriously  sup- 
plied with  nerves  also,  which  arise  from  the  same  mixed  ciliary  nerves  that  give  to  the 
cornea  its  exquisite  sensitiveness.  But  while  the  trigeminous  fibers  play  the  most  impor- 
tant part,  if  not  the  only  role,  in  the  cornea,  the  iris  depends  upon  fibers  from  trigeminus, 
ocolomotor,  and  sympathetic :  this  explains  the  presence  of  the  ganglia  in  the  iris  and 
choroid,  although  these  are  of  microscopic  smallness.  The  stroma  of  the  iris  is  a  fibril- 
lar}' connective  tissue  having  anteriorly  a  loose  envelope  of  endothelial  cells.  In  the 
more  anterior  layers  there  are  numerous  star-shaped  pigment-cells,  the  amount  of  which 
decides  the  color  of  the  iris,  or,  as  the  laity  say,  '•  the  color  of  the  eye."  Blue  irides 
have  no  pigment  ceils,  the  blue  color  being  but  an  interference  phenomenon  due  to  the 
pigment  deposit  at  the  back. 

The  ciliary  body  consists  of  the  ciliary  processes  and  ciliuty  muscle.  Examined  by 
the  microscope,  ii  is  seen  that  the  muscle  is  composed  of  unstriated  muscle-fibers  that  run 
in  three  different  directions  {Fig.  g^).  The  external  group  arises  from  the  inner  wall  of 
the  canal  of  Schlemm  and  passes  backward  in  the  direction  of  a  principal  meridian  to  be 
inserted  in  the  choroid.  This  is  called  Bruecke's  muscle,  or  the  "  tensor  choroideae."  A 
second  group  arises  in  the  same  place,  but  passes  rather  toward  the  center  of  the  eye,  the 
so-called  radial  fibers.  The  third  group  has  a  circular  course  around  the  eye,  and  is 
called  Mueller's  muscle  (seen  in  Fig.  g4  in  transverse  section). 

The  liliar}- processes  {Fig.  g^)  consist  principally  of  blood-vessels,  hut  there  are  a  few 
connective-tissue  fibers  and  pigment-cells.  Their  {xjsterior  surface  is  covered  by  a  vitre- 
ous membrane  of  a  double  layer  of  epithelial  ceils,  one  of  which,  directly  against  the  pro- 
cesses, is  richly  pigmented,  and  is  a  continuation  of  the  pigment  epithelium  of  the  retina ; 
the  second  and  inner  layer  (inner  referring  to  the  direction  within  the  eye)  consists  of 
cylindrical  cells  lacking  pigment.  Both  layers  are,  on  morphological  grounds,  called 
pars  ciliiiris  retitue. 

The  choroid  is  a  membrane  from  o.oS  to  0.16  mm.  thick,  composed  chiefly  of  blood- 
vessels. In  transverse  section  there  is  seen  between  the  vessels  a  faint  stroma  of  elastic 
fibers,  with  numerous  star-shaf)ed  pigment  cells.  These  vessels  are  arranged  in  groups, 
the  lai^er  ones  externally,  next  a  layer  medium-sized,  and  internally  is  the  chorio-capil- 
laris.  a  dense  network  of  minute  vessels,  which  is  closer  woven  the  nearer  it  approaches 
the  area  of  acutest  vision  in  the  subjacent  retina.  The  chorio  capillaris  is,  therefore,  ab- 
sent behind  the  ciliary  processes — the  so-called  orbiculus  ciliaris.  The  inner  surface  of 
the  choroid  is  covered  by  a  transparent  membrane  of  extraordinary  thinness.  The  outer 
surface  is  covered  by  loose,  reduplicated  tissue,  composed  of  endothelial  cells  and  called 
lamina  suprachorioidea . 

The  blood-vessels  in  the  uveal  tract  (Fig.  ^j). — In  the  human  Ixxly  an  artery  is 
usually  accompanied  by  two  veins,  within  which  the  blood  from  that  artery  flows  back  to 
the  heart.  The  circulation  in  the  eye  is  arranged  in  quite  a  different  manner.  We  find 
here  two  distinct  arterial  territories,  an  anterior  and  a  posterior,  and  the  blood  from  them 
is  carried  off  in  a  venous  system  lying  between.  The  posterior  arterial  stream  flows 
through  the  ai-teritr  ciliares  posttcii  brerrs,  about  20  small  arterioles  penetrating  the 
sclera  near  the  posterior  pole  of  the  eyeball,  to  mei^e  at  once  into  the  capillary  network 
of  the  choroid.  The  anterior  arterial  stream  flows  through  two  arteria  ciliares  postica 
longir  and  se^'en  arterite  ciliares  anticce.  The  two  long  posterior  arteries  penetrate  the 
sclera  at  the  posterior  pole,  and  pass  forward,  without  subdividing,  to  the  nasal  and  tem- 
poral side  of  the  eye,  between  sclera  and  choroid,  where  each  sends  a  descending  and  an 
ascending  branch  to  the  ciliary  body ;  the  two  ascending  branches  on  the  one  side,  and 


268  DISEASES    OF    THE    MIDDLE    TUNIC    OF    THE    EVE. 

the  two  descending  branches  on  the  other,  meet  to  become  united  in  the  circulos  arterio- 
sus iridis  major.  The  seven  anterior  ciliary  arteries  that  arise  from  the  muscular  arteries 
of  the  orbit,  and  pierce  the  external  coat  of  the  eye  near  the  sclero-comeal  margin,  pour 
their  contents  into  the  same  arterial  circle.  From  this  circle  arise  numerous  arteries 
supplying  iris  and  ciliary  body.  When  the  blood  has  here  become  venous,  it  is  collected 
into  the  small  veins  that  pass  backward  -toward  four  to  six  points  at  the  equator,  where, 
united  into  one  large  vessel,  they  abruptly  pierce  the  sclera  posteriorly.  Toward  these 
same  points  at  the  equator  pass  the  veins  that  have  received  the  blood  from  the  choroidal 
capillaries — that  is,  the  posterior  arterial  stream.  This  venous  current  forms  a  kind  of 
whirlpool,  so  that  the  four,  five,  or  six  collecting  veins  have  been  called  the  veme  7'orti- 


GruituJOrtfrtifjar 


Ca/nera pas/rru>r 


\ 


zArterui  ciZuirtj 
eixtica^ 


.\ 


-Una  yoriiaxsa 


-Arierca.  cdians 
postica  ionM 

'Artifria  ci/iaris 
/>oitica  ireru 


-Artfrta  ceiitmlti 
'VHnae 


Fig.  95. — Blood-Vbsskls  of  the  Eyk.     {After  Leber.) 
Arteries,  red  ;  veins,  black. 

cos(V.  However,  that  the  principle  of  the  circulation  may  not  be  contradicted,  a  small 
quantity  of  blood  escapes  from  the  eyeball  through  the  veni^  ciliares  antiae  et  postica, 
which  take  a  course  parallel  to  the  arteries  of  the  same  name.  The  anterior  veins  are, 
in  the  living  body,  visible  through  the  ocular  conjunctiva,  particularly  after  the  disease 
to  be  described  later  on  as  chronic  inflammatory  glaucoma.  The  general  principle  of  the 
circulation  is  still  further  preserved,  in  that  the  anterior  and  posterior  arterial  streams 
form  an  anastomosis  through  the  minute  vessels  in  the  orbiculus  ciliaris. 

2.  PHYSIOLOGICAL  INTRODUCTION. 
These  three  subdivisions  of  the  uveal  tract  have  dilferent  functions,  as  might  be  sup- 
posed from  the  difference  in  their  structure ;  these  functions  being  analogous,  however, 


PHYSIOLOGICAL    INTRODUCTION.  269 

as  might  be  supposed  from  their  common  richness  in  pigment  and  blood-vessels.  All 
optical  instruments — the  microscope,  telescope,  etc., — are  blackened  inside  so  as  to 
absorb  any  stray  rays  of  light  and  to  nullify  their  effect.  The  eye  also  is  blackened  by 
the  pigment  of  the  uvea.  The  richness  in  blood-vessels  enables  the  uvea  to  secrete  a  thin, 
fluid  lymph.  The  eye  has  not  distinct  lymph  vessels,  but  there  are  lymph  spaces,  the 
fluid  in  which  courses  in  two  different  directions.  Within  the  eye  the  anterior  and  pos- 
terior chambers  {J-'ig.  95)  form  one  space,  while  the  "  canalis  Cloqueti,"  or  the  "  central 
canal  of  the  vitreous,"  forms  the  second.  Since  the  fluid  contents  of  these  lymph  spaces 
has  only  a  trace  of  albumin,  and  therefore  cannot  be  a  simple  transudate  from  the  uveal 
vessels,  we  must  consider  this  fluid  an  evidence  of  lymph-secreting  cells,  and  we  assume 
that  the  pars  ciliaris  retinse,  particularly  the  unpigmented  cells  on  the  back  of  the  ciliary 
body,  plays  the  part  of  such  a  glandular  structure.  This  much  is  certain,  and  can  be 
demonstrated  by  injecting  fluorescin  into  the  circulation  of  a  rabbit,  that  there  is  a  current 
from  the  posterior  chamber  through  the  pupil  into  the  anterior  chamber.  This  current 
passes  from  the  pupil  toward  the  circumference  of  the  anterior  chamber  (the  filtration 
angle)  and  escapes  through  the  network  there  into  the  canal  of  Schlemm  and  the  anterior 
ciliary  veins.  It  is  possible  that  some  fluid  from  the  anterior  chamber  is  sucked  up  by 
the  sponge-like  tissue  of  the  iris,  to  be  carried  off  through  the  ciliary  body  and  the  vorti- 
cose veins.  The  fluid  in  the  central  canal  of  the  vitreous  probably  originates  in  the  same 
way  from  the  cylindrical  cells  of  the  ciliary  Ixidy,  and  it  flows  backward,  leaves  the  eye  by 
the  side  of  the  optic  nerve,  and  continues  its  course  in  the  lymph  fissures  between  the 
sheaths  of  the  nerve. 

The  iris  has  a  special,  optical  task — the  regulation  of  the  amount  of  light  entering  the 
eye.  A  luminous  point  will  obviously  send  the  more  light  to  the  retina — circumstances 
being  otherwise  the  same — the  larger  the  pupil  is.  Since,  with  a  wide  pupil,  bright 
objects  would  produce  retinal  images  whose  intensity  would  be  injurious  to  the  retina, 
the  nervous  mechanism  is  so  adjusted  \\\2i\.  the  pupil  contracts  xuhen  the  quantity  of  im- 
pinging light  is  great,  and  dilates  when  this  quantity  is  small.  If  the  contraction  was 
excessive,  the  pupil  dilates  a  bit  immediately  afterward,  and  it  may  thus  fluctuate  with 
alternate  contraction  and  dilatation  until  its  size  is  exactly  proportionate  to  the  amount  of 
illumination. 

Sharp  retinal  images  will  be  formed  only  of  such  objects  as  send  luminous  rays  to  the 
cornea  under  a  small  angle  of  entrance.  If  the  pupil  is  of  medium  width,  this  condition, 
for  objects  at  infinity,  is  fulfilled  by  the  iris,  which  shuts  off  peripheral  rays  striking  the 
cornea  under  a  large  angle  ;  but  if  the  object  lies  within  a  few  decimeters  of  the  eye, 
some  of  the  diverging  rays  strike  a  portion  of  the  cornea  not  yet  cut  out  by  the  iris,  at  a 
large  angle  of  entrance.  The  result  would  be  an  indistinct  retinal  image,  if  it  were  not 
that  the  nervous  mechanism  is  so  arranged  that  a  contraction  of  the  pupil  takes  place  when 
a  near  object  is  looked  at ;  by  this  means  all  but  th^  small  central  portion  of  the  cornea  is 
cut  out,  and  through  this  area  luminous  rays  pass  nearly  perpendicularly,  in  spite  of  the 
proximity  of  the  object.  Moreover,  the  contraction  of  the  pupil  is  not  accomplished 
directly  by  near  fixation  alone,  but  stands  in  intimate  relation  to  accommodation  and 
convergence.  If  the  accommodation  is  made  unnecessary  by  proper  lenses,  and  the 
convergence  equally  so  by  prisms,  the  pupil  does  not  contract,  in  spite  of  near  fixation. 

Contraction  of  the  pupil  by  light,  accommodation,  and  convergence  occurs  simultane- 
ously in  both  eyes,  even  if  one  eye  is  excluded  from  vision  by  being  covered.  Inequality 
of  the  pupils — anisokoria — is,  therefore,  without  exception,  pathological.  Besides  light, 
accommodation,  and  convergence,  other  conditions  have  their  influence  on  the  width  of 
the  pupil.  A  congestion  of  blood  in  the  irilic  vessels  causes  contraction  of  the  pupil,  as, 
for  example,  the  systolic  wave,  and  the  increase  of  blood  pressure  in  expiration  ;    while 


270  DISEASES    OF    THE    MIDDLE    TUNIC    OF    THE    EYE. 

strong  irritation  of  some  sensitive  nerves  and  severe  muscular  exercise  cause  dilatation. 
Purely  psychical  forces  liave  their  effect,  such  as,  for  example,  the  contraction  of  the 
pupil — Haab's  reflex — caused  when  attention  is  directed  to  some  object  at  the  side  while 
the  eye  itself  does  not  change  its  position. 

Mydriatic  and  myotic  drugs  are  of  great  importance  in  ophthalmology,  since  their 
effect  may  be  produced  by  local  application  as  well  as  by  introduction  into  the  circu  a- 
tion.  These  remedies  are  used  as  solutions,  salves,  or  in  the  dry  form,  for  application 
to  the  conjunctiva.  The  drug  is  diffused  through  the  cornea  into  the  anterior  chamber, 
and  acts  either  directly  on  the  muscles  of  the  iris  or  on  the  nerve  endings  in  them. 

Mydriatics. — Those  most  used  to  dilate  the  pupil  are:  .Sulfate  of  atropin,\\ydro- 
bromate  of  honiatropin,  and  muriate  of  cocain.  Atropin  and  homatropin  paralyze  the 
sphincter  of  the  pupil  and  stimulate  the  dilatator  at  the  same  time.  This  last  is  taken 
for  granted,  because  a  dilated  pupil  subsequent  to  oculomotor  paralysis  can  be  still 
further  dilated  by  atropin.  Cocain  affects  the  dilatator  chiefly,  stimulating  it ;  this  is 
assumed  from  the  fact  that  a  pupil  dilated  by  cocain  is  still  subject  to  contraction  when 
influenced  by  light,  accommodation,  and  convergence;  the  sphincter  cannot  possibly, 
therefore,  be  paralyzed  as  it  is  by  atropin. 

Mydriatics  act  on  the  muscle  of  accommodation  (musculus  ciliaris)  besides  affecting 
the  size  of  the  pupil.  Atropin  paralyzes  it  completely,  and  leaves  the  eye  adjusted  for 
its  far  point  only ;  honiatropin  paralyzes  it  incompletely,  while  cocain  but  moderately  de- 
presses its  function.  The  effect  of  the  strongest  mydriatic,  atropin,  lasts  the  longest, 
about  eight  days ;  that  of  homatropin  about  a  day,  and  that  of  cocain  only  a  few  hours. 
Of  course,  the  amount  of  the  drug  used  must  be  considered.  Oiher  effects  of  mydriatics 
have  already  been  mentioned  on  /.  226,  and  still  others  will  be  discussed  under  "  Glau- 
coma." It  may  be  merely  stated  here  that  cocain  stimulates  the  end  fibers  of  the 
sympathetic,  and  produces  thereby  a  contraction  of  the  unstriated  levator  {fig.  ^7)  with, 
the  accompanying  widening  of  the  palpebral  fissure. 

Miotics. — Eserin  sulfate  or  salicylate,  and  pilocarpin  muriate  are  those  most  used. 
Both  stimulate  the  sphincter  pupillae  to  a  powerful  tonic  contraction,  the  result  being  to 
reduce  the  pupil  to  the  size  of  a  pinhead.  It  is,  however,  not  rigid  but  mobile,  although 
to  a  very  limited  degree.  The  ciliary  muscle  is  stimulated  to  a  spasmodic  contraction, 
and  the  eye  is  therefore  adjusted  for  the  near  point  only.  After  very  small  doses  of  the 
drug,  and  after  the  spasmodic  action  has  passed  off,  the  ciliary  muscle  is  strengthened,  a 
condition  that  may  be  proved  by  the  increased  range  of  accommodation.  The  spasmodic 
muscular  contractions  make  themselves  felt  in  the  eye  as  twitchings  or  "  painful  jerk- 
ings. "  In  sensitive  persons  there  are  occasional  fibrillary  twitchings  in  the  musculus  or- 
bicularis palpebrarum,  which  are  felt  by  the  patient  and  seen  through  the  skin.  The 
effect  of  eserin  on  the  iris  may  lead  to  a  true  iritis  ;  the  use  of  the  milder  pilocarpin  is  not 
accompanied  by  this  danger.  For  the  effect  of  myotics  on  the  internal  tension,  see 
"  Treatment  of  Glaucoma." 

In  addition  to  the  mydriatics  and  myotics  already  mentioned  there  are  other  similarly 
acting  drugs  any  of  which  may  be  at  times  used  in  place  of  the  customary  ones.  Mor- 
p/iin,  muscarin,  and  nicotin  are  myotics ;  scopalainin,  hyoscyatiiin  (the  same  as  duboisin) 
and  gelsemin  are  mydriatics.  Dilatation  of  the  pupil  is  caused  by  certain  ptomains  that 
develop  in  rotting  meat  and  may  reach  the  blood  through  the  stomach. 

The  physician,  when  using  a  mydriatic  or  a  myotic,  should  never  for  an  instant  forget 
that  these  drugs  are  powerful  poisons  ;  that  fluid  may  escape  through  the  lacrimal  pas- 
sages to  act  on  the  nose  and  throat ;  that  many  persons  are  particularly  sensitive  to  them  ; 
and  that  intoxication  or  poisoning  has  been  the  result,  most  commonly  from  atropin. 
The  symptoms  are  tickling  and  dryness  in  the  throat,  vomiting,  diarrhea,  redness  of  the 


* 

HYPEREMIA — INFLAMMATIONS.  2/1 

face,  quick  and  irregular  pulse.  Death  itself  has  been  caused  by  "  eye-drops."  All 
danger  may  be  easily  avoided,  no  matter  how  often  the  drug  is  applied,  by  directing  the 
patient  always  to  press  the  finger  firmly  against  the  lacrimal  sac  for  ten  minutes  after 
dropping  the  medicine  into  his  eye.  If  minute  doses  are  used  such  precautions  may  be 
omitted. 

A.  DISEASES  OF  THE  IRIS. 

I.  HYPEREMIA. 

Hyperemia  of  the  iris  is  not,  strictly  speaking,  a  disease,  but 
merely  a  token  of  disease,  which  may  accompany  a  large  number 
of  inflammations  of  the  eye.  It  is  necessary  to  describe  it  by  itself, 
however,  since  to  reach  a  correct  prognosis  a  sharp  distinction 
must  be  made  between  hyperemia  and  inflammation  of  the  iris. 
Hyperemia  is  recognized  by  three  objective  signs : — 

(/)  Narrowing  of  the  pupil — explainable,  perhaps,  mechanically 
by  the  increased  volume  of  blood  in  the  vessels  of  the  iris.  The 
pupil  can  be  narrowed  in  this  way,  as  may  be  easily  demonstrated 
by  injecting  fluid  into  the  vessels  of  the  iris  of  an  eye  of  a  corpse.' 

{2)  Discoloration^  recognized  by  the  mixture  of  red  with  the  pre- 
dominant color  of  the  individual  iris  ;  for  example,  a  brown  iris  when 
hyperemic  becomes  reddish  ;  a  blue  iris,  greenish  ;  a  gray-blue  iris, 
greenish-yellow. 

( j)  Sluggish  reaction  to  atropin,  the  pupil  becoming  only  mode- 
rately dilated  by  that  drug,  and  this  half  mydriasis  disappearing 
much  more  rapidly  than  under  normal  circumstances.  In  hypere- 
mia there  is,  moreover,  ciliary  injection,  photophobia,  and  lacri- 
mation.  Hyperemia  of  the  iris  accompanies  all  severe  inflamma- 
tions of  the  conjunctiva,  such  as  acute  trachoma,  blennorrhea,  diph- 
theria ;  all  severe  irritations  to  the  cornea,  such  as  that  from  a 
foreign  body  or  ulcer;  and  all  inflammations  of  the  ciliary  body 
and  choroid. 

2.  INFLAMMATIONS. 

If  the  hyperemia  becomes  so  pronounced  that  an  exudate  is 
formed,  there  is  a  genuine  inflammation — an  iritis.  Four  kinds  of 
iritis  are  distinguished,  according  to  the  nature  and  the  location  of 
this  exudate. 


^  The  mere  removal  of  the  fluid  pressure  upon  the  iris  well  suffices  to  contract  the 
pupil.  This  may  be  done  on  the  cadaver  by  allowing  the  aqueous  to  escape,  while  dila- 
tation may  be  produced  by  injecting  fluid  into  the  anterior  chamber.  How  these  eftects 
are  produced  is  not  quite  clear,  nor  are  authors  in  haimony  on  this  point. 


272  DISEASES    OF    THE    MIDDLE   TUNIC   OF    THE    EYE. 

(a)  An  extremely  scant,  fibrinous  exudate  is  deposited  upon  the 
anterior  or  posterior  surface  of  the  iris,  the  pigment  layer  at  the 
edge  of  the  pupil  becoming  thereby  adherent  in  places  to  the  cap- 
sule of  the  lens — synechia  posterior.  This  form  of  iritis  is  called 
simple  or  plastic  iritis. 

{b)  An  inflammatory  product,  poor  in  cells,  settles  into  the  ante- 
rior chamber  to  mix  with  the  aqueous  and  to  be  deposited  upon 
the  posterior  surface  of  the  cornea.    This  form  is  called  serous  iritis. 

(c)  An  inflammatory  product  rich  in  pus  cells  saturates  the 
tissues  of  the  iris,  and  its  overflow  settles  into  the  anterior  chamber 
as  a  hypopyon.     This  form  is  called  purulent  iritis. 

[d)  Finally,  it  may  happen  that  some  cells  adhere  to  isolated 
points,  to  grow  into  nodules  by  means  of  a  delicate  connecting 
substance.     This  form  may  therefore  be  spoken  of  as  nodular  iritis. 

Of  course,  every  case  cannot  be  made  to  fit  into  this  category. 
Intermediate  forms  are  not  uncommon.  Many  a  case  begins  as  a 
serous  iritis  and  changes  during  the  course  of  weeks  into  a  plastic 
iritis.  Again,  in  a  pronounced  plastic  iritis,  deposits  upon  the  back 
of  the  cornea  are  by  no  means  unusual,  nor  should  it  be  forgotten 
that  posterior  synechia,  the  diagnostic  sign  of  plastic  iritis,  may 
accompany  every  form  of  the  inflammation. 

{a)  Iritis  Simplex  seu  Plastica. — The  patient  complains  of  pain, 
photophobia,  lacrimation,  and  dimness  of  vision.  The  pain,  the 
same  ciliary  neuralgia  mentioned  under  diseases  of  the  cornea, 
radiates  from  the  eye  to  forehead  and  temple,  even  to  the  upper 
jaw  and  nose,  and  is  particularly  distressing  at  night.  Pain  is  not 
always  proportionate  to  the  severity  of  the  disease,  the  lacrimation 
and  photophobia  being  in  this  respect  much  more  trustworthy 
guides.  Many  patients  have  no  symptoms,  and  consult  a  physician 
merely  because  the  eye  is  clouded.  In  looking  at  an  affected  eye 
there  is  noticed  : — 

(/)  Pericorneal  injection,  in  which  the  red  color  due  to  the  blood 
increases  in  intensity  accordingto  the  severity  of  the  inflammation; 
the  extent  of  this  redness  likewise  differs  accordingly. 

{2)  A  loss  of  the  velvety  blackness  of  the  pupil ;  this  is  the  result 
of  a  moderate  haziness  of  the  aqueous,  and  may  be  distinguished 
from  corneal  opacity  by  focal  illumination  (/.  g8). 

(j)  A  loss  of  smootJ in  ess  and  polish  in  the  iris,  which  is  discolored, 
and  its  "  relief"  is  not  so  easily  recognized.  This  is  the  result  of  a 
delicate  fibrinous  exudate  upon  the  back  of  the  iris. 


COURSE   AND    CONSEQUENCES.  2/3 

(^)  A  contracted,  immovable,  unsymmetrical pupil.  The  posterior 
synechise  protrude  into  the  pupillary  area  as  small,  brown  dotlets. 
This  condition  is  detectable  only  by  means  of  focal  illumination 
and  a  lens  or  by  the  use  of  atropin.  If  such  an  eye  is  strongly 
atropinized,  the  edge  of  the  iris  lags  behind  at  the  points  of  adhe- 
sion, and  forms  sonlewhat  horseshoe-like  protrusions  {Fig.  g6). 
Atropin  is,  therefore,  an  indispensable  aid  to  the  diagnosis  of  iritis. 
Unfortunately,  its  use  is  often  neglected,  and  many  a  case  of  iritis 
falls  into  the  ophthalmologist's  hands  only  after  it  has  been  mis- 
treated as  a  conjunctivitis,  with  zinc  solution  or  something  similar. 

(j)  Hyperemia  of  the  optic  nerve  is  said  to  accompany  iritis  almost 
without  exception.  I  am  free  to  doubt,  however,  whether  this  can 
always  be  seen  through  the  opacities  in  the  pupil. 

Course  and  Consequences. — An  acute  iritis  may  run  its  course 
in  two  to  four  weeks,  even  without  treatment,  and  yet  leave  no  par- 


FiG.  96. — Posterior  Synechia,  by  Transillumination,  after  Atropin.     (After  Jaeger.) 

ticular  disturbance  in  its  trail.  The  exudate  becomes  absorbed  ;  the 
adhesions  are  broken  up  by  the  ceaseless  activity  of  the  play  of  the 
pupil.  Only  the  ophthalmologist  is  able,  by  means  of  focal  illumi- 
nation and  the  lens,  to  detect  dotlets  of  pigment  upon  the  anterior 
lens  capsule, — the  unabsorbed  remnants  of  the  adhesions.^ 

Such  a  favorable  course  must  be  an  exception  in  untreated  cases. 
It  is  rather  the  rule  that  adhesions  of  the  iris  to  the  capsule  of  the 
lens  become  permanent  by  the  change  of  the  exudate  into  connect- 
ive tissue  ;  this  new-formed  connective  tissue  looks — with  focal  il- 
lumination— grayish-white.    Such  a  permanent  adhesion  is,  of  itself, 


'  Schubert  has  called  attention  to  the  fact  that  in  about  every  fifth  blue  eye,  and  in 
every  second  brown  eye,  however  henlthy,  a  kind  of  pigment  dust  may  be  detected  on 
the  anterior  lens  surface ;  but  this  has  nothing  in  common  with  pathological  deposits  of 
pigment. 

18 


274 


DISEASES    OF   THE    MIDDLE   TUNIC    OF    THE    EYE. 


no  great  misfortune,  as  the  visual  acuity  need  not  be  especially  im- 
paired thereby;  but  it  must  be  remembered  that  the  iris  is  extra- 
ordinarily inclined  to  relapses,  and  that  adhesions  but  increase  this 
tendency.  The  greatest  danger  to  vision  lies  in  the  circumstance 
that  the  entire  pupil  may  be  filled  with  exudate  during  a  severe 
inflammation,  that  this  exudate  may  become  organized  into  a  con- 
nective-tissue membrane,  and  that  vision  is  necessarily  reduced 
thereby  to  the  mere  perception  of  light — a  condition  called  occlu- 
sion of  the  pupil. 

This  is  by  no  means  the  worst  that  can  happen.  An  occluded 
pupil  need  cause  no  further  disturbance,  for  the  eye  may  remain  in 
this  condition  for  years,  and  even  then  a  useful  visual  acuity  may 
be  restored  by  an  iridectomy.     But  matters  change  when — with  or 


-Aflterinr  C/tam/ier 

~Jfer/i/>rftne 

Synt'rJt/a 

- 1  frtip/tiffl  /ri^. 

Jii////t't/ />f>st/>rior 
(Viam/'er. 

Zt'Tif  ofZ/nn-. 


Fig.  97. — Circular  Synechia  with  Occlusion  of  the  Pupil.    (After  Pagcnstecher  ami  Cenlh.) 

without  occlusion  of  the  pupil — repeated  relapses  result  in  forming 
a  circular  adhesion  between  lens  and  iris  {Fig.  gf).  Now,  the 
aqueous  accumulating  in  the  posterior  chamber  has  no  way  of 
escaping  into  the  anterior  chamber.  The  iris  bulges  forward,  the 
eye's  tension  increases,  and  if  an  artificial  pupil  is  not  at  once  pro- 
duced so  as  to  reestablish  the  connection  between  posterior  and 
anterior  chambers,  the  eye  will  be  hopelessly  lost  from  the  result- 
ing increase  of  pressure  within  it.  The  most  important  element  in 
the  treatment  of  iritis  must  therefore  be  the  effort  to  prevent  or  to 
overcome,  as  far  as  possible,  these  adhesions  between  iris  and  lens. 
General  Causes. — These  may  be  separated  into  idiopathic  (pri- 
mary) and  consecutive  (secondary).  A  secondary  iritis  results  as 
a  consequence  of  severe  inflammations  of  the  cornea,  sclera,  cili- 
ary body,  or  choroid;  even  a  blennorrhea,  that  is,  a  conjunctival 


TREATMENT    OF    PLASTIC    IRITIS.  2/5 

inflammation,  may  lead  to  an  iritis.  An  iritis  from  an  injury 
{iritis  traumatica)  is  probably  due  to  both  idiopathic  and  consecu- 
tive conditions.  Of  itself,  a  cut,  a  laceration,  or  even  a  bruise  need 
not  cause  an  iritis;  but  if  the  injury  is  made  with  unclean  instru- 
ments, or  if  the  conjunctival  sac  was  not  at  the  time  quite  free 
from  bacteria,  the  result  will  be  an  iritis,  although  it  need  not  be  of 
a  threatening  character.  From  purely  chemical  causes,  too,  from 
irritation  by  swollen  lens  substance,  or  by  an  oxidizing  bit  of  metal, 
for  example,  there  may  be  an  iritis  produced. 

An  idiopathic  iritis,  where  the  iris  alone  is  involved,  is  probably 
always  the  result  or  the  manifestation  of  some  general  dyscrasia.^ 
In  the  first  rank  as  a  cause  stands  syphilis.  Mauthner  says  that 
60  per  cent,  to  75  per  cent,  of  all  cases  are  due  to  syphilis.  Others 
are  satisfied  with  a  smaller  percentage  ;  but  we  may  at  least  ascribe 
one-half  of  all  cases  to  this  disease.  It  is  often,  but  not  always, 
easy  to  detect  the  syphilitic  nature  of  an  iritis  objectively.  Small 
papules  {iritis  papulosa)  or  particularly  broad  synechiae,  congestion 
of  isolated  areas  of  the  iris,  and  a  moderate  brine-like  exudate  into 
the  anterior  chamber  all  indicate  syphilis. 

Tuberculosis,  according  to  Michel,  is  nearly  as  common  a  cause 
of  iritis  as  syphilis.  This  view  seems  unsupported  by  other  observ- 
ers. Proof — the  detection  of  the  tubercle  bacillus — is  in  most  cases 
lacking,  since  an  opportunity  for  a  microscopic  examination  is  not 
often  presented.  We  shall,  however,  discuss  later  on  a  form  of  iritis 
that  is  undoubtedly  of  tubercular  origin.  Articular  rheumatism, 
gout,  gonorrheal  inflammation,  diabetes,  albuminuria,  severe  infec- 
tive diseases  like  typhoid  fever,  small-pox,  and  recurrent  fever,  are 
all,  in  a  decreasing  ratio,  causes  of  iritis.  Finally,  there  are  a  few 
cases  of  iritis  in  which  none  of  the  causes  enumerated  can  be  dis- 
covered. A  universally  popular  explanation  is  "  catching  cold." 
The  physician  must  be  satisfied  with  the  term  "  idiopathic." 

Treatment. — From  what  has  been  said  it  is  clear  that  the 
general  physical  condition  must  be  carefully  examined  in  any 
case  of  plastic  iritis ;  syphilis  must  be  particularly  traced  and, 
if  positively  found,  treated.  If  the  examination  is  negative,  the 
local  treatment  must  begin  with  decided  atropinization.  The  best 
plan  is  to  place  in  the  conjunctival  sac  a  kernel  of  some  salt  of 


^  The  only  circumstance  that  cannot  be  made  to  accord  with  this  proposition  is  the  fact 
that  iritis  often  occurs  on  one  side  only. 


2/6  DISEASES    OF   THE    MIDDLE   TUNIC    OF   THE    EYE. 

atropin  about  the  size  of  a  pin-head,  and  have  the  patient  press 
on  the  tear-sac  for  fifteen  minutes.  If  the  adhesions  are  broken 
up,  if  the  pupil  becomes  round  and  dilated,  it  is  a  probable  token 
that  the  power  of  the  disease  is  overcome  and  that  a  rapid  im- 
provement may  be  expected.  If  the  effect  of  the  atropin  is  un- 
satisfactory, try  next  a  5  per  cent,  solution  of  cocain,  a  drop  every 
three  minutes  for  five  doses,  and  then  use  another  kernel  of  atropin 
on  the  conjunctiva  with  the  same  care  to  prevent  intoxication. 
If  on  the  next  day  no  decided  improvement  is  evident  and  if  the 
synechiae  seem  not  yet  broken  up,  apply  six  to  eight  leeches  to  the 
temple  and  repeat  the  cocain  and  atropin.  If  there  is  still  no  effect, 
no  time  should  be  lost  before  beginning  mercurial  inunctions,  even 
if  syphilis  is  not  demonstrable.  Healthy  adults — and  these  are  the 
patients  most  usually  attacked — can  tolerate  a  daily  inunction  of  5.0 
grains  of  the  unguentuni  hydrargyrum  cinereum ;  weaker  patients 
should  use  smaller  doses,  j.o,  2.0,  or  i.o  gram  daily.  If  the  iritis 
is  severe,  a  warm  bath  and  profuse  diaphoresis  should  be  ordered 
before  each  inunction.  Of  course,  the  mouth  should  be  carefully 
watched  meanwhile.  Ail  this  time  the  local  treatment  with  cocain 
and  atropin  must  be  continued.  The  effect  of  this  energetic  mer- 
curial treatment  is  remarkable  ;  at  the  end  of  the  first  week  decided 
improvement  will  be  observed,  even  in  the  worst  cases ;  the  inflam- 
mation will  subside,  the  adhesions  will  be  to  some  extent  loosened, 
and  the  noticeably  reduced  visual  acuity  will  begin  to  be  restored. 
In  four  weeks  the  cure  will  be  about  complete.  Pain,  which  often 
robs  the  patient  of  his  night's  rest,  may  be  combated  by  warm  appli- 
cations to  the  eye,  by  quinin  0.2  gram  or  antipyrin  o.j"  gram  inter- 
nally, as  occasion  demands,  and  in  the  worst  cases  by  morphin 
o.oi  gram  hypodermatically.  If  all  such  means  fail,  a  corneal 
puncture  with  release  of  the  aqueous  will  bring  about  immediate 
ease  from  pain ;  to  be  sure,  the  pain  returns  as  soon  as  the  former 
tension  is  restored,  but  it  is  seldom  so  distressing,  and  the  corneal 
puncture  maybe  repeated.  If  a  circular  synechia  and  the  resulting 
heightened  tension  has  not  been  avoided,  the  inflammation  should 
be  no  bar  to  the  performance  of  an  iridectomy;  but  if  even  the 
slightest  connection  remains  between  anterior  and  posterior  cham- 
bers, enough  to  exclude  any  immediate  danger  to  the  optic  nerve, 
the  iridectomy  should  be  postponed  until  the  inflammatory  storm 
has  passed.  In  no  case  should  the  patierit  be  discharged  before  an 
iridectomy  is  performed,  if  the  adhesions  are  so  plentiful  or  so  extensive 


IRITIS   SEROSA.  2// 

as  to  threaten  a  total  synechia  duri?ig  any  future  relapse.  Severe  cases 
of  iritis  should  be  confined  to  bed  in  a  dark  room  ;  in  milder  cases 
the  patient  may  go  about,  but  should  give  up  all  work,  reading 
especially.  The  eye  must  be  protected  against  strong  light  by 
smoked  glasses.     Alcohol  and  stimulating  food  are  to  be  avoided. 

{U)  Iritis  Serosa. — This  is  of  a  decidedly  chronic  character  and 
shows  few  of  the  signs  of  inflammation.  The  neighborhood  of  the 
cornea  is  a  delicate  rose  color.  The  patient  seldom  complains  of 
more  than  a  cloud  before  the  eyes  and  some  dazzling.  Objectively 
it  is  seen  that  the  inflammatory  products  are  deposited  in  the  ante- 
rior chamber  and  on  the  posterior  surface  of  the  cornea  [Fig.  88,  see 
also  pp.  24.6  and  ^^7),  and  not,  as  in  plastic  iritis,  on  the  iris  or  within 
the  pupil.  The  aqueous  is  hazy  and  increased,  this  increase  being 
recognized  by  the  greater  depth  of  the  anterior  chamber  and  the 
heightened  tension  of  the  globe.  The  pupil  is  of  medium  size, 
the  iris  a  trifle  discolored  and  sluggish  in  its  movements.  The 
disc,  which  at  this  stage  of  the  disease  can  be  quite  well  seen,  is 
distinctly  hyperemic,  the  retinal  veins  tortuous  and  swollen. 

If  the  disease  advances,  the  deposits  on  the  back  of  the  cornea 
increase  and  coalesce,  forming  semilunar  lines.  Wherever  these 
lines  are  found  we  may  expect  opacities  in  the  posterior  corneal 
layers,  which  never  quite  clear  up.  Posterior  synechiae  and  vitre- 
ous opacities  are  other  common  results,  the  latter  proving  that  the 
ciliary  body  has  been  sympathetically  attacked — iridocyclitis  serosa. 

Serous  iritis  most  usually  occurs  in  young  persons,  particularly 
in  young  anemic  women.  Uterine  derangements  and  inherited 
syphilis  have  been  called  causes.  Since  serous  iritis  is  bilateral,  as 
a  rule,  it  is  doubly  proper  to  search  for  some  general  dyscrasia, 
although  this  inflammation  is  often  a  purely  local  disease  occurring 
after  cataract  operations. 

Prognosis  is  more  favorable  than  that  of  plastic  iritis,  in  so  far  as 
a  complete  cure  may  take  place  without  synechiae  or  other  sequelae, 
but  it  is  more  unfavorable  on  account  of  the  great  tendency  serous 
iritis  has  to  involve  the  posterior  portions  of  the  uveal  tract,  and 
thus  seriously  to  injure  or  even  to  destroy  the  eye.  The  chronic 
course  of  serous  iritis  (six  to  eight  weeks)  must  also  be  taken  into 
account. 

Treatment. — Owing  to  the  fact  that  the  patient  is  usually  poorly 
nourished  and  in  weak  physical  condition,  a  depressing  mercurial 
treatment  cannot  be  attempted.     It  is  better  to  try  to  raise  the 


2/8  DISEASES    OF   THE    MIDDLE    TUNIC    OF    THE    EVE. 

patient's  strength  by  proper  food  and  regimen.  Diaphoresis,  small 
doses  of  iodid  of  potassium  or  of  iodid  of  iron,  encourage  the 
absorption  of  the  inflammatory  products.  Locally,  atropin  in  small 
quantity,  say  twice  a  day  a  drop  of  a  5^  per  cent,  solution,  is  ser- 
viceable in  keeping  the  pupil  dilated  and  in  breaking  up  any  acci- 
dental adhesions.  Repeated  corneal  punctures  to  release  the  aque- 
ous are  very  useful,  since  the  deposits  are  mechanical!}'  removed 
thereby,  and  absorption,  even  of  vitreous  opacities,  is  noticeably 
encouraged. 

(<:)  Iritis  Suppurativa. — In  this  form  the  inflammatory  products 
— pus  cells — are  deposited  within  the  iris  itself,  and  in  suppurative 
iritis  the  most  prominent  sign  is  an  increase  in  the  thickness  of  the 
iris.  A  more  pj'ononnced  discoloratiofi  also  characterizes  it ;  the  color 
may  become  quite  yellow.  Hyperemia  is  so  intense  that  by  using 
a  lens  the  vessels  can  be  clearly  distinguished  ;  in  some  cases  they 
may  be  seen  to  have  ruptured  and  to  have  allowed  blood  to  escape 
into  the  anterior  chamber.  The  pus  cells,  collecting  in  the  anterior 
chamber,  form  a  hypopyon,  which  is  in  two  ways  different  from  that 
of  "  ulcus  serpens  corneae  "  {p.  22g) :  it  consists  solely  of  pus  cells 
(not,  as  in  ulcus  serpens,  of  both  fibrin  and  pus  cells),  and  therefore 
changes  its  location  as  the  head  is  moved — a  condition  not  so  easy 
for  a  compact  clot  composed  of  both  pus  cells  and  fibrin.  Again, 
this  hypopyon  is  susceptible  of  such  a  rapid  absorption  that  no 
trace  of  it  may  be  detected  on  the  next  day.  The  pupil  is  distorted 
by  a  fibrinous  or  purulent  exudate.  It  may  be  stated  that  this  form 
is  rare  nowadays,  since  one  of  the  chief  sources  of  suppurative  iritis, 
infection  by  a  wound,  has  been  overcome  by  antisepsis.  Another 
cause,  diabetes,  is  still  of  moderate  influence. 

Prognosis  is  doubtful,  since  there  is  danger  that  the  disease  may 
pass  to  the  choroid  and  lead  to  suppuration  of  the  eyeball.  Cases 
are  seen,  however,  due  to  some  obscure  cause,  in  which  the  hypo- 
pyon and  the  entire  disease  disappear  as  quickly  and  as  mysteriously 
as  they  come.^  Suppurative  iritis  from  diabetes  usually  ends  favor- 
ably. 

Treatment  should  commence  with  rapid  inunctions  ;  in  diabetes, 
with  salicylate  of  sodium.  Locally,  atropin  should  be  used,  and 
after  the  severer  inflammation  has  passed,  the  clouded  aqueous 
with  its  hypopyon  should  be  released  by  corneal  puncture. 


1  A  case  of  choroidoretinitis  that  I  have  just  treated  ran  exactly  this  course. 


IRITIS    NODOSA.  2/9 

(d)  Iritis  Nodosa  {^Iritis  gummosa  et  tuberculosa). — A  collecting 
of  cells  into  small  nodules  may  occur  in  both  plastic  and  suppura- 
tive iritis,  but  it  has  no  characteristic  appearance  in  any  one  case. 
There  are  cases,  however,  in  which  the  nodules  attain  the  size  of  a 
millet  seed,  a  pea,  or  even  of  a  bean,  and  are  therefore  of  the  great- 
est diagnostic  importance,  since  they  are  seated  upon  a  healthy  or 
nearly  healthy  iris.  These  nodules  are  either  small  gummata  or 
tubercles ;  in  the  first  case  we  speak  of  iritis  gummosa,  in  the 
second,  of  iritis  tuberculosa. 

Gummata  are  most  always  solitary,  rarely  are  there  three  or  four. 
A  gumma  sits  at  the  pupillary  edge  or  (less  frequently)  at  the  cili- 
ary edge  of  the  iris,  in  the  latter  case  being  below  and  inward.  Its 
size  is,  according  to  Alexander's  observations,  that  of  half  a  pea  to 
half  a  hazelnut.  It  has  a  brownish-yellow  or  even  a  yellow  color,  and 
is  surrounded  by  a  brownish-red  base  composed  of  blood-vessels. 

Tubercles  are  usually  in  groups.  The  nodules  are  at  some  dis- 
tance from  the  pupillary  edge  and  sit  with  preference  on  the  lower 
half  of  the  iris.  The  color,  grayish-white  or  whitish-yellow,  is 
essentially  lighter  than  that  of  a  gumma.  The  adjacent  lymph 
glands  of  the  same  or  of  both  sides  are  swollen.  The  physician 
should  always  make  a  careful  examination  of  the  general  condition 
of  the  patient,  and  try  to  detect  the  history  or  the  presence  of  syph- 
ilis or  tuberculosis  on  other  parts  of  the  body.  Tubercular  iritis 
usually  attacks  young  persons  up  to  the  twentieth  year,  gumma- 
tous iritis  those  in  more  advanced  life. 

Treatment. — Iritis  gummosa  is  cured  when  the  cells  disappear, 
but  there  is  left  in  their  stead  a  cicatricial  connective  tissue.  The  iris 
is  essentially  changed  in  appearance  thereby,  its  blue  becoming  gray, 
its  brown,  grayish-brown ;  the  details  of  the  surface  of  the  iris  are  no 
longer  to  be  recognized  ;  its  motility  is  diminished  or  lost.  Such  an 
iris  is  atrophic;  atrophy  of  the  iris  is  therefore  always  to  be  feared 
when  any  inflammatory  product  has  been  deposited  within  its  tissue. 

Iritis  gummosa  is,  like  gumma  of  other  parts  of  the  body,  an  expression  of  late  or 
tertiary  syphilis,  and  is  consequently  to  be  treated  with  iodid  of  potassium,  not  with  mer- 
cury.    The  inflammation  is  to  be  attacked  as  in  iritis  plastica. 

Iritis  tuberculosa  is  divided  by  Haab  into  two  groups.  In  the  lesser  of  these,  nodules 
are  formed,  increase,  cause  much  distress,  and  gradually  disappear.  They  leave  the  eye 
in  a  tolerable  condition,  or  they  may  set  up  a  chronic  choroiditis  that  may  finally 
destroy  it.  The  other  and  large  group  is  evidenced  by  pronounced  hypertrophies  that  fill 
the  anterior  chamber  and  penetrate  the  cornea  at  last,  so  that  the  eye  atrophies  (phthisis). 
Such  cases  were  formerly  called  i'ranuloiiia  of  the  iris. 


iIk  eve 


«rtie 


«rijbe 


I  VtcA 
mKSher 
Ml  vet 


3.  ISICnSS  ASD  FOHEKSe  BOUES. 

Wp  iiM»  rf  tfce  in 

tDdbeletts.    A  woHai of  tie  ins 

a  fart:,  ■eedk.akitor 

mm    ■Mr  mBBHHHBHBDOlL  ■■■    BCSHC  uK   WCKm 


INJURIES    AND    FOKEIGN    BODIES. 


281 


dicular  to  the  sclera  till  it  has  reached  the  anterior  chamber,  when 
the  handle  is  depressed  so  as  to  bring  the  blade  parallel  to  the 
surface  of  the  iris  ;  the  knife  is  now  pushed  forward  till  the  external 
wound  is  large  enough*  for  the  particular  purp>ose  of  the  operation. 
As  the  blade  is  withdrawn  the  handle  should  be  still  more  depressed, 
so  that  the  point  of  the  knife  is  in  contact  with  the  p>osterior  surface 
of  the  cornea,  since  by  this  means  an  injur}'  to  the  advancing  lens 
is  best  avoided.  The  fixation  forceps  are  now  given  to  an  assistant ; 
the  iris  forceps,  closed,  are  thrust  through  the  wound  to  the  edge 
of   the  pupil,   then   opened  so  as  to  seize   the   iris   between   its 


Fig.  9S. — Lid  SpBCCLmt. 


Fig.  99. — Ancuulk  Keka- 

TOKE. 


Fig.  100. — Spatct-x  fc'E 
Reflacikg  the  Iris. 


branches ;  the  iris  is  drawn  out  of  the  wound  far  enough  to  see  the 
pigment  layer  at  the  back,  when  a  portion  of  it  is  cut  off  by  the 
scissors  held  with  firm  pressure  against  the  eyeball  and  parallel  to 
the  wound.  Fi^:  loi  shows  the  result  after  a  proper  excision,/^. 
102  the  not  unusual  case  where  a  corner  of  the  pupillary-  edge  has 
been  drawn  into  the  wound.  Here  the  effort  should  be  made  to 
replace  this  edge,  either  by  stroking  the  cornea  with  a  Daviel's 
spoon  or  by  entering  the  spatula  into  the  anterior  chamber  and  so 
thrusting  the  iris  directly  into  place.  If  this  does  not  succeed,  the 
iris  forceps  and  scissors  must  be  used  again  to  excise  the  incarcerated 


282 


DISEASES    OF   THE    MIDDLE    TUNIC    OF    THE    EYE. 


bit  of  iris.     All  antiseptic  precautions  necessary  and  the  after-treat- 
ment are  discussed  under  the  operation  for  cataract  {q.  v). 

The  commonest  foreign  bodies  in  the  iris  are  splinters  of  wood, 
stone,  iron,  or  copper.  Eyelashes,  or  the  h^irs  of  animals,  are  less 
frequent.  An  aseptic  foreign  body  upon  or  in  the  iris  may  be  tol- 
erated for  years,  but  no  dependence  can  be  placed  on  this.  As  a 
rule,  inflammation  is  soon  set  up.  Since  any  foreign  body  in  the 
iris  or  anterior  chamber  is  difficult  to  remove  after  the  aqueous  has 
become  clouded,  it  must  always  be  removed  at  once.  This  is  by 
no  means  easy  if  it  has  dropped  into  the  iritic  angle.  For  its  re- 
moval an  incision  should  be  made  at  the  scleral  border  with  a 
Graefe's  knife  (/7V  72(5),  and  an  attempt  made  to  grasp  the  object  with 
a  Daviel's  spoon,  a  forceps,  or  (if  it  is  iron)  with  the  magnet ;  if  this 
does  not  succeed,  or  if  it  seems  inadvisable  to  attempt  it  on  account 


Fig.  ioi. — Key-hole  Coloboma.thk  Edges  of 
THB  Iris  being  in  theik  Proper  Place. 


Fig.  102. — Incarceration  of  the  Iris  in 
THE  Wound  (at  the  Right). 


of  iritis,  it  is  best  to  enter  the  iris  forceps  open,  to  seize  the  iris  to 
the  right  and  left  of  the  foreign  body,  to  enclose  the  object  within 
this  fold,  and  to  perform  an  immediate  iridectomy. 

Parasites  in  the  iris  are  discussed  under  Parasites  {q.  v). 


4.  NEW  GROWTHS. 

(rt)  Cysts. — True  and  false  cysts  are  found  in  the  iris.  A  genuine  cyst  protrudes  from 
the  iris  as  a  whitish  transparent  nodule,  with  a  clear  fluid  contents  and  a  cyst  wall  of 
very  thin  iris  tissue  having  an  internal  layer  of  epithelial  cells.  A  false  cyst  is  an 
atheromatous  tumor ;  it  is  round  and  yellow,  not  transparent ;  its  contents  is  not  fluid 
but  mushy,  and  consists  of  epidermal  cells  concentrically  arranged. 

The  origin  of  these  formations  has  been  much  discussed,  but  a  satisfactory  conclusion 
is  not  yet  reached.  There  is  no  doubt  that  some,  especially  the  atheromatous,  cysts 
arise  from  invasion  of  the  iris  by  corneal  epithelium.  These,  as  well  as  most  of  the 
genuine  cysts,  originate  after  some  previous  penetrating  wound  of  the  cornea,  from  which 
corneal  epithelial  cells  have  been  crowded  into  the  iris.     An  earlier  injurj-  is  therefore 


TUMORS — MEMBRANA    PUPILLARIS    PERSEVERANS.  283 

• 
an  extremely  important  factor  in  determining  whether  a  cyst  is  of  the  atheromatous  or 
nodular  variety. 

These  new  growths  endanger  the  eye  when  they  grow  large  enough  to  set  up  inflam- 
mation or  to  increase  the  tension.  They  should,  therefore,  be  completely  removed  by  an 
iridectomy. 

(b)  Tumors. —  Occasionally  there  is  in  the  iris  a  pigmented  or  unpigmented  tumor, 
shown  to  be  malignant  by  its  rapid  growth,  and  to  be  a  sarcoma  by  its  histologic  struc- 
ture;  usually  a  melanosarcoma,  rarely  a  leukosarcoma. 

Benign  tumors  on  the  iris  or  extending  into  the  anterior  chamber  are  recorded.  The 
pigmented  edge  toward  the  pupil  has  occasionally  small  pigmented  nodules,  such  as  are 
normal  in  the  horse's  eye,  where  they  are  sometimes  loosened  by  the  activity  of  the  pupil. 

Rapid  growth  in  any  tumor  should  suggest  malignancy. 


5.  CONGENITAL  MALFORMATIONS. 

[n)   Albinism. — The  essential  characteristic  of  this  condition  is  a  lack  of  pigment, 
not  necessarily  in  the  iris  alone,  but  in  all  parts  of  the  body,  so  that  the  whole  body  ap- 
pears lighter-colored  than  normal.     Lack  of  pigment  in  the  middle  and  inner  retinal 
layers  causes  dazzling  and  photophobia.      Albinos  often  suffer 
from  active  movements  of  the  iris,  from  nystagmus,  and  from 
diminished   visual   acuity.     The  condition   is  a  morphological 
defect,  explainable  when  we   remember  that  the   formation  of 
pigment  takes  place  during  the  latter  months  of  fetal  life  and 
after  birth,  and  that  every  embryo  is,  therefore,  albinotic  up  to 
a  certain  stage  of  its  life. 

(/')  Heterochromia, — We  sometimes  see  a  person  whose 

eyes  are  not  of  the  same  color,  or  whose  irides  may  have  sectors 

of  different  colors.      In  other  cases  dark  or  light  blotches  may         jr,Q   ,q, Congenital 

be  irregularlv  scattered  over  the  iris.     Many  such  persons  reach  ^°''°^°", ^,  C^^'J" 

?  '     .  .  .  ...  Bridge).     {After  Sce- 

a  certain  notoriety  by  the  superstition  of  imaginative  observers,  misch.) 

who  see  indications  of  letter  formation — the  word  Napoleon, 

for  example — in  these  blotches.      Anxious  mothers  often  observe  these  irregularities  in 

the  eyes  of  their  children  and  ask  the  physician's  advice  about  them. 

(t)  Coloboma. — This  is  the  most  frequent  defect  in  the  iris.  The  aperture  in  it 
gives  to  the  pupil  an  egg-  or  pear-shaped  appearance.  This  aperture  lies  regularly  beneath, 
or  beneath  and  to  the  nasal  side  of,  the  pupil  {Fig.  loj).  It  is  due  to  an  incomplete  clos- 
ure of  the  optic  fissure  in  the  fetus.  The  aperture  may  nearly  disappear  as  adult  life  is 
reached.  There  are  seldom  visual  disturbances  due  to  the  defect,  but  if  any  are  present, 
they  can  be  usually  traced  to  a  corresponding  defect  in  the  choroid — coloboma  choroidete. 

(d)  Corektopia  is  the  term  used  to  describe  a  displacement  of  the  pupil ;  it  is  usually 
downward  and  inward,  and  is,  to  a  certain  extent,  but  an  exaggeration  of  the  pupil's 
normal  excentricity  (/.  266).      Displacements  in  other  directions  are  rare. 

[e]  Irideremia  is  the  lack  of,  or  a  mere  suggestion  of,  iris.  The  condition  is  always 
bilateral,  while  coloboma  is  nearly  always  unilateral.  The  extraordinarily  large  pupil 
is  not  a  deep  black,  but  rather  gray  or  even  red.  ^ 

(/)  Membrana    Pupillaris    Perseverans. — This  term  describes  a  condition   in . 

^  The  optical  reasons  for  this  phenomenon  are  given  in  the  study  of  the  illumination 
of  the  eye  (  /.  gg).      Dazzling  and  reduced  vision  are  very  noticeable. 


284  DISEASES    OF    THE    MIDDLE    TUNIC    OF   THE    EYE. 

which  fibers  springing  from  the  anterior  surface  of  the  iris  pass  over  the  pupil  to  be 
attached  to  the  anterior  surface  of  the  lens  (/v^T-  f04)-  ^l  '''  "ot  proper  to  consider  this 
as  a  continuation  of  the  iris  inward.  It  is  rather  the  remnant  of  a  vascular  connective- 
tissue  layer  that  in  the  embryo  envelojied  the  lens  before  the  iris  had  been  formed.  The 
fibers  are  so  long  and  elastic  that  they  offer  no  hindrance  to  the  play  of  the  pupil.  They 
usually  cause  no  visual  disturbances. 

6.  CHANGES  IN  SIZE  AND  MOTILITY  OF  THE  PUPIL. 
The  diameter  and  activity  of  the  pupil  are  .subject  to  .such  great 
variations  during  health  that  there  must  be  a  decided  dilatation  or 
contraction  before  the  condition  can  be  called  pathological.     We 
do  not  know  why  one  individual  has  narrow  pupils,  while  another, 
under  exactly  the  same  circumstances — illumination,  accommoda- 
tion, and  convergence — has  wide  pupils.     We   do   know  that   the 
newborn    have    very    small    pupils,    young 
people  large  and  active  pupils,  and  that  the 
pupils  of  the  old  are  again  narrow  and  slug- 
gish.    It  is  an  easy  matter,  however,  to  dis- 
cover any  disturbance  in  size  or  motility  of 
one  pupil,  if  it  can  be  compared  with  the 
other.    Always,  therefore,  search  for  any  pos- 
.sible  inequality  between  the  two  {anisokona). 
If  anisokoria  is  detected,  the  next  problem 

Fig.  104. — Membrana  Pupil- 

LARis  persevekans.  (w//?r      is  to  determine  which  pupil  is  diseased — the 

IVicherkieivicz.) 

narrower  or  the  wider  one.  To  answer  this 
the  pupil  must  be  set  in  motion;  and  that  pupil  which  shows  the 
lesser  activity  when  the  illumination  is  changed  or  when  the  object 
looked  at  is  approached  to  or  withdrawn  from  the  far  and  near 
points,  may,  as  a  rule,  be  considered  the  diseased  one. 

There  is  still  another  question:  What  is  the  pathology ?  Is  a 
pupil  dilated  by  paralysis  of  the  sphincter  or  by  spasm  of  the  dila- 
tator? Or  is  a  pupil  contracted  by  spasm  of  the  sphincter  or  by 
paralysis  of  the  dilatator?  As  a  matter  of  fact,  all  these  conditions 
are  possible.  A  conclusion  can  be  reached  either  by  demonstra- 
tion or  exclusion.  Let  us  assume  that  we  have  a  patient  with  a 
dilated  and  rigid  pupil :  obviously  there  must  be  a  paralysis  of  the 
sphincter.  Among  the  causes  of  this  paralysis  the  commonest  is 
atropin,  and  the  patient  should  always  be  asked  whether  his  eye 
has  been  previously  treated  by  some  one  else.^ 

^  A  short  time  ago  there  was  brought  to  me  a  little  patient  with  dilated  and  rigid  pupils. 
I  told  the  father  that  atropin  or  some  such  poison  must  have  been  applied.     The  father 


CHANGES    IN    SIZE    AND    MOTILITY    OF   THE    PUPIL.  285 

If  atropin  or  other  mj-driatics  (/.  2yd)  are  out  of  the  question, 
we  must  bear  in  mind  the  possibility  of: — 
(i)  Glaucoma; 

(2)  Injury,  and 

(3)  Disease  of  the  oculomotor  nerve. 

Paralysis  of  the  sphincter  is  also,  as  a  rule,  combined  with  paraly- 
sis of  the  ciliary  (accommodative)  muscle. 

In  cases  of  dilated  pupils  due  to  spasm  of  the  dilatator,  the 
patients  are  not  apt  to  ask  advice.  They  are  usually  insane  per- 
sons in  a  delirious  condition,  or  patients  suffering  from  severe  dysp- 
nea, or  those  in  uremic,  epileptic,  or  eclamptic  convulsions, — 
patients,  therefore,  in  whom  the  dilatation  of  the  pupil  is  of  second- 
ary importance.  Of  course,  spasmodic  dilatation  of  the  pupil  may 
be  produced  by  milder  diseases  if  they  cause  irritation  to  the  sym- 
pathetic ;  other  evidences  of  this  irritation  will  be  discoverable, 
however,  such  as  vesicles  of  that  side  of  the  face  and  widening  of 
the  palpebral  fissure  (Mueller's  muscle  supplied  by  the  sympathetic). 
Intestinal  worms  have  been  accused  of  causing  moderate  irritation 
of  the  sympathetic. 

A  pathologically  contracted  pupil  is  rarer  than  a  pathologically 
dilated  one.  It  results  from  spasm  of  the  sphincter  produced  by 
eserin  or  pilocarpin  as  well  as  from  hyperemia  or  beginning  inflam- 
mation of  the  iris,  or  from  oculomotor  irritation  due  to  inflamma- 
tion of  the  brain  and  its  membranes.  As  a  rule,  there  is  an  accom- 
panying spasm  of  the  ciliary  (accommodative)  muscle.  Paralysis 
of  the  dilatator  causes  miosis  when  the  medulla  or  spinal  cord  is 
affected  by  injury  or  inflammation.     This  is  called  spinal  miosis. 

Finally  it  must  be  mentioned  that  in  monocular  blindness  the 
pupil  of  the  blind  eye  no  longer  reacts  to  light  falling  upon  it,  but 
does  react  in  harmony  with  the  sound  eye  when  this  latter  is  illu- 
minated or  changes  during  an  effort  at  accommodation.  This  "  con- 
sensual movement,"  that  is,  contraction  of  one  pupil  due  to  illumi- 
nation of  the  other  eye,  cannot,  of  course,  be  present  in  the  healthy 
eye  when  the  blind  eye  is  stimulated. 

Eyes  with  good  visual  acuity  may  show  a  "  reflex  pupillary  rig- 
idity," that  is,  loss  of  reaction  to  light  stimulation,  although  normal 


declared  that  it  wns  not  possible.  I  insisted  on  a  thorough  investigation,  assuring  him 
that  we  should  discover  something.  The  next  day  he  came  back  to  say  that  the  child 
had  squirted  the  juice  of  the  thorn-apple  (stramonium)  into  his  eye  I 


286  DISEASES    OF   THE    MIDDLE   TUNIC    OF    THE    EYE. 

reaction  to  accommodation  and  convergence  may  still  be  present. 
This  is  of  the  gravest  significance,  since  it  is  a  sign  of  beginning 
spinal  cord  disease — tabes  dorsalis. 

Hippus  is  a  clonic  spasm  of  the  sphincter  pupillK,  by  means  of  whicli  a  rapid  change 
in  the  size  of  the  pupil  takes  place  without  external  cause.  The  disease  is  usually 
associated  with  nystagmus.      It  need  produce  no  visual  disturbance. 

Iris  Tremulans,  Iridodonesis. — A  healthy  iris  neither  trembles  nor  oscillates,  thanks 
to  the  fact  that  the  lens  offers  a  firm  and  smooth  -support  upon  which  the  iris  glides. 
But  if  the  lens  is  crowded  very  much  to  the  rear,  as  in  myopia,  for  example,  or  as  the 
result  of  atrophy  of  the  vitreous,  or  if  the  lens  shrivels,  as  it  does  in  overripe  cataract,  or 
if  it  is  lacking,  as  it  always  is  after  cataract  extraction,  the  iris  has  no  support,  and  it 
trembles. 


B.    DISEASES  OF  THE  CILIARY  BODY. 

I.   CYCLITIS. 

Inflammations  of  one  division  of  the  uveal  tract  have  an  extraor- 
dinary tendency  to  involve  the  other  divisions.  This  tendency  is 
most  clearly  seen  in  inflammations  of  the  ciliary  body.  The  iris  is 
always  more  or  less  involved,  so  that  inflammation  of  the  ciliary 
body  is  called  by  many  authors  iridocyclitis,  and  if  the  choroid  is 
simultaneously  affected,  iridocyclochoroiditis. 

Cyclitis  is  always  a  serious,  often  a  dangerous,  disease,  and  must 
therefore  be  sharply  differentiated  from  the  relatively  benign  iritis. 
This  distinction  is,  however,  not  an  easy  one,  because  they  both 
have  in  common  the  symptoms  of  pain,  photophobia,  lacrimation, 
and  obscured  vision.  It  is  necessary,  therefore,  carefully  to  search 
for  those  signs  that  characterize  cyclitis  alone.     These  are  : — 

(i)  Sensitiveness  to  pressure  in  the  ciliary  region  ; 

(2)  Cloudiness  in  the  anterior  portion  of  the  vitreous  ; 

(3)  Noticeable  changes  in  the  intraocular  tension,  increased  at 
first,  diminished  in  the  later  stages  of  the  diseases. 

Sensitiveness  to  pressure  is  often  so  pronounced  that  the  patient 
shrinks  back  with  a  start  if  the  ciliary  region  (particularly  the 
upper  and  outer  area)  is  only  lightly  touched,  while  many  a  patient 
is  made  unconscious  by  it. 

Three  forms^  are  described  :  serous,  plastic,  and  purulent  cyclitis. 


1  A  fourth  might  be  cyclitis  nodosa,  since  gummata  of  the  ciliary  body  have  been  re- 
ported, which  involved  the  iris  only  supplementarily.      They  are  extremely  rare,  however. 


CVCLITIS    SEROSA — CVCLITIS    PLASTICA. 


287 


Cyclitis  serosa  is  comparatively  benign,  developes  like  a  serous 
iritis  (/».  i"//),  and  cannot  be  clearly  separated  from  it. 

Cyclitis  plastica  is  the  worst  form.  It  begins  with  the  signs  of 
severe  inflammation  accompanied  by  swelling  of  the  conjunctiva 
and  lids.  The  inflammatory  product  is  deposited  chiefly  in  the 
posterior  chamber  and  in  the  more  anterior  portion  of  the  vitreous  ; 
it  thus  encourages  adhesion  between  the  back  of  the  iris  and  the 
lens  (^Fig.  loj),  and  after  becoming  organized  into  a  connective-tissue 
membrane  it  produces  a  very  extensive  adhesion  between  Jens  and 
iris,  which  is  called  synechia  posterior  totalis.     It  is  characterized  by 


Fig.  105. — Total  Postekior  Synechia.     (After  Pagenstecher  and  Genth.) 
The  adhesion  between  iris  and  lens  is  so  extensive  as  to  obliterate  the  posterior  chamber. 


the  depth  of  the  anterior  chamber,  particularly  at  the  filtration 
angle.  There  may  be  membranous  formations  in  the  vitreous  as 
well.  The  nutrition  of  the  lens  suffers  so  severely  on  this  account 
that  total  or  partial  opacity  of  the  lens  is  unavoidable.  As  this 
pathological  membrane  contracts,  it  carries  the  disasters  of  detach- 
ment of  the  retina  and  atrophy  of  the  eyeball  in  its  trail.  Plastic 
cyclitis  results  in  the  great  majority  of  all  cases  immediately  or 
sometime  after  an  injury  to  the  ciliary  body.  Foreign  bodies  within 
the  eye  are  almost  certain  to  destroy  the  eye  by  a  plastic  cyclitis 
(see  Injuries  to  the  Globe).  Idiopathic  cases  are  said  to  have 
resulted  from  syphilis,  tuberculosis,  and  diseases  of  the  uterus. 


288  DISEASES    OF   THE    MIDDLE   TUNIC    OF   THE    EYE, 

Cyclitis  suppurativa  runs  a  stormy  course.  It  is  distinguished 
from  plastic  iritis  by  the  presence  of  hypopyon,  and  of  a  purulent 
exudate  behind  the  lens  which  was  formerly  called  hypopyon  pos- 
ticu.n.  It  is  characteristic  of  purulent  cyclitis  that  the  hypopyon 
comes  and  goes  very  quickly — it  may  disappear  within  a  few  hours 
If  purulent  cyclitis  involves  the  choroid  there  is  danger  of  that  con- 
dition c^Wtd  pa7tophthal)nitis/\n.  which  the  whole  eyeball  suppurates 
and  finally  atrophies.  Such  an  ending  is  nearly  always  unavoidable 
if  purulent  cyclitis  is  due  to  infection  after  injury  or  operation. 
Purulent  cyclitis  ending  in  atrophy  is  said  to  follow  severe  infective 
diseases  (small-pox,  scarlet  fever).  Occasionally  a  purulent  cyclitis 
from  some  unknown  internal  cause  may  run  a  favorable  course. 

Treatment  of  cyclitis,  taken  altogether,  is  that  of  iritis,  but 
atropin  must  be  used  with  caution,  as  it  is  often  poorly  borne.  In 
serous  cyclitis  the  not  unusual  appearance  of  increased  tension 
demands  particular  care.  To  reduce  this  tension  the  local  use 
of  cocain  is  of  service,  as  may  be  also  diaphoresis  by  subcutaneous 
pilocarpin  injections.  If  success  is  not  reached,  a  corneal  puncture 
should  be  tried,  and  may  be  repeated  every  second  day  if  circum- 
stances warrant.  Plastic  and  purulent  cyclitis  may  be  treated  with 
an  impressive  course  of  mercurial  inunction ;  whether  or  not  this 
really  helps  is  questionable.  When  the  inflammatory  phenomena 
have  completely  subsided,  an  iridectomy  should  be  performed.  The 
disease  tends  to  relapse,  even  after  years  have  passed,  and  an 
iridectomy  may  help  to  prevent  such  an  accident,  but  unfortunately 
the  operation  has  not  always  the  desired  result,  since  the  aperture 
in  the  iris  may  close  up  or  the  inflammation  be  lighted  up  anew. 
Purulent  cyclitis  after  an  operation  is  much  rarer  nowadays,  thanks 
to  antisepsis  ;  if  it  does  occur,  even  the  worshipers  of  mercury  will 
not  resort  to  inunctions,  but  will  restrict  themselves  to  local  treat- 
ment with  atropin,  antiseptic  douches,  and  warm  compresses. 

Very  recently  subconjunctival  injections  of  mercury  have  been  tried  (about  0.00003 
of  the  bichlorid  at  a  dose)  at  intervals  of  three  to  four  days.  A  definite  statement  as  to 
the  efficacy  of  this  method  cannot  at  present  be  given.  My  own  experience  has  not 
been  very  encouraging. 

2.  PARALYSIS  AND  SPASM  OF  THE  CILIARY  MUSCLE. 
Paralysis  or  Paresis  of  the  ciliary  muscle  is  evidenced  by  a 
destruction  of,  or  a  diminution  in,  the  range   of  accommodation. 
Since  the  range  of  accommodation  becomes  smaller  with  the  senile 


PARALYSIS    OR    PARESIS.  289 

changes  in  the  lens  (/.  ^5),  a  paralysis  of  the  ciliary  muscle  should 
not  be  diagnosticated  unless  the  range  of  accommodation  in  a 
healthy  lens  is  demonstrably  smaller  than  that  which- corresponds 
to  the  age  of  the  patient.  Usually,  but  not  always,  some  dilatation 
of  the  pupil  (/».  2^6)  is  associated  with  a  paralysis  or  paresis  of  the 
ciliary  muscle.  The  optical  conditions  are  discussed  in  the  section 
on  "  The  Range  of  Accommodation  "  (/.  ^i). 

Another  occasional  result  is  Micropsia.  We  estimate  the  size  of  an  object  according 
to  the  size  of  its  retinal  image,  and  according  to  the  distance  at  which  we  suppose  it  to 
be.  If  the  retinal  image  of  an  object  remains  unchanged,  it  appears  to  us  either  small  or 
large,  according  as  we  think  of  it  as  far  or  near.  For  example,  a  fly  in  the  air  may  seem 
to  us  to  be  a  large  bird  a  long  way  off.  In  estimating  the  distance  of  any  object  we  see, 
the  feeling  of  effort  we  have  made  for  the  sake  of  accurate  dioptric  adjustment  plays  an 
important  part.  But  since  a  patient  with  a  weakened  ciliary  muscle  makes  a  great  effort 
to  adjust  his  eye  for  a  certain  object,  he  thinks  it  must  be  nearer  than  it  actually  is.  If 
the  object  were  actually  at  the  place  he  supposes,  its  retinal  image  would  be  much  larger 
than  it  really  is  ;   consequently  it  appears  smaller  to  him. 

The  causes  of  paresis  or  paralysis  may  be  peripheral  or  central, 
that  is  to  say,  the  ciliary  muscle  itself  (or  the  nerve  fibers  ending 
in  it)  may  be  paralyzed,  or  the  passage  of  a  nervous  stimulation 
may  be  prevented.  For  example,  atropin  causes  a  peripheral  paraly- 
sis ;  that  caused  by  disease  of  the  oculomotor  nucleus  (see  Paraly- 
ses of  the  Eye  Mtiscles  {q.  v.)  is  central.  A  paralysis  may  be  caused 
by  intoxication  (ptomaines,  diphtheria,  etc.),  or  by  weakness  (pro- 
longed confinement,  excesses,  loss  of  blood,  exhausting  diseases), 
the  seat  of  the  trouble  being  then  indeterminate. 

Treatment  depends  upon  the  cause,  and  therefore  is  usually 
general.     Locally,  glasses,  eserin,  and  electricity  may  be  tried. 

If  there  is  spasm  of  the  ciliary  muscle,  the  far  point  of  the  eye 
draws  nearer,  that  is,  the  emmetrope  becomes  apparently  myopic, 
the  myope  still  more  myopic,  and  the  hyperope  less  hyperopic 
than  that  which  corresponds  to  the  shape  of  the  globe.  The  range 
of  accommodation  is  therefore  shortened  but  not  destroyed.  The 
near  point  also  draws  nearer,  but  relatively  less  so  than  the  far 
point.  Since,  then,  a  weaker  effort  than  usual  suflfices  to  attain 
a  certain  effect,  objects  are  supposed  to  be  further  off  than  they 
really  are,  and  consequently  they  are  estimated  to  be  too  large — 
tnacropsia. 

As  causes,  eserin  and  pilocarpin  may  be  named,  as  well  as  the 
strain  on  accommodation  resulting  from  hyperopia,  or  from  hold- 
ing books  too  close,  or  from  weakness  of  the  muscles  of  converg- 
19 


290  DISEASES    OF   THE    MIDDLE    TUXIC    OF    THE    EYE. 

ence,  for  if  the  proper  convergence  can  be  attained  only  by  a  par- 
ticularly strong  effort  of  the  will,  an  unduly  powerful  impulse  is 
at  the  same  time  given  to  the  muscle  of  accommodation.  Finally, 
spasm  of  the  ciliary  muscle  with  miosis  is  often  a  sign  of  severe 
spinal-cord  disease. 

Treatment. — Spasm  of  the  ciliary  muscle  may  be  overcome  by 
atropin  ;  but  if  it  is  of  central  origin,  the  spasm  naturally  returns 
as  soon  as  the  action  of  the  drug  passes  off. 


C.    DISEASES  OF  THE  CHOROID. 

I.  SCLEROCHOROIDITIS  ANTERIOR. 

This  disease  involves  the  anterior  part  of  the  choroid,  inaccessi- 
ble to  the  ophthalmoscope.  The  inflammation  is  at  first  local, 
leading  to  the  development  of  an  episcleral  nodule  (/>.  262).  At 
this  stage  it  is  difficult  or  impossible  to  diagnosticate  sclerochoroi- 
ditis  anterior  from  episcleritis.  The  results,  however,  make  a  diag- 
nosis easy,  since  episcleritis  is  always  a  benign  local  disease,  but 
anterior  sclerochoroiditis  shows  a  pronounced  inclination  to  spread 
out  on  the  surface,  to  attack  the  cornea  and  iris,  to  produce  opaci- 
ties in  the  anterior  portion  of  the  vitreous,  and,  by  raising  the  ten- 
sion, to  cause  ectasia  of  the  sclera.  The  disease,  with  occasional 
improvement  or  subsidence,  lasts  for  years,  and  finally  leads  to 
blindness  through  flatness  and  opacity  of  the  cornea,  increased  ten- 
sion, and  change  in  form  of  the  eyeball.  The  causes  are  not  well 
defined  ;  rheumatism,  gout,  or  syphilis  may  be  suspected. 

Treatment  can  be  successful  only  in  the  beginning.  Mercury 
and  diaphoresis  are  said  to  be  of  service.  Tension  must  be  care- 
fully watched,  and  in  suitable  cases  should  be  lowered  by  corneal 
puncture  or  iridectomy.  These  operations  are  occasionally  success- 
ful in  putting  an  end  to  an  already  beginning  sclerectasia. 

Sclerochoroiditis  posterior  (sclerectasia  posterior,  staphyloma  posticum)  is  dis- 
cussed in  the  section  on  Refractive  Errors,  under  Myopia  {q.  v."). 

2.  CHOROIDITIS  EXUDATIVA. 

This  disease  is  not,  as  might  be  supposed  from  the  name,  supple- 
mentary to  plastic  iritis  and  cyclitis.  There  is,  of  course,  such  a 
supplementary  inflammation  of  the  choroid,  that  is,  a  choroiditis 


CHOROIDITIS    EXUDATIVA — CHOROIDITIS    DISSEMINATA.  29I 

with  pain  and  abundant  exudation  into  the  vitreous  (opacitates 
corporis  vitrei),  but  nothing  is  to  be  gained  by  describing  it  by  it- 
self, since  it  is  always  an  accompaniment  of  inflammation  of  the 
entire  uveal  tract  (iridocyclochoroiditis),  and  cannot  be  traced 
with  the  ophthalmoscope  on  account  of  these  opacities  in  the  ante- 
rior segment  of  the  eye.  Diagnosis,  in  particular  cases,  can  be 
made  only  from  the  disproportion  between  visual  power  and  these 
opacities. 

The  various  diseases  grouped  under  the  name  of  choroiditis 
exudativa  are  essentially  distinguishable  from  the  above,  in  that 
they  run  their  course  without  pain,  without  redness  of  the  eye,  in 
short,  without  any  signs  of  inflammation  perceptible  externally. 
The  patient  in  many  cases  is,  therefore,  aware  of  his  trouble  only 
when  vision  is  impaired  by  involvement  of  the  retina.  There  are 
cases,  however,  in  which  the  patient  comes  to  the  physician  com- 
plaining of  flickerings  in  front  of  the  eyes,  sparks,  and  night-blind- 
ness, all  of  which  indicate  some  disease  of  the  choroid.  Externally, 
nothing  is  visible  on  the  eye  affected,  but  with  the  ophthalmoscope 
and  the  aid  of  tests  for  visual  acuity  and  visual  field  the  disease 
may  be  diagnosticated  in  all  its  details  of  location,  character,  and 
extent,  and,  according  to  the  ophthalmoscopic  appearance  may  be 
differentiated  into  choroiditis  disseminata,  choroiditis  areolaris 
(Foerster),  and  choroiditis  circumscripta  centralis  (chororetinitis 
centralis). 

Choroiditis  disseminata  is  characterized  by  the  presence  on 
the  fundus  of  numerous  dispersed  patches  {Fig.  J06),  which  are 
thickly  strewn  near  the  equator,  but  more  sparsely  further  back, 
leaving  the  posterior  pole,  that  is,  the  region  of  the  disc  and  mac- 
ula lutea,  comparatively  free.  This  appearance  arouses  the  sus- 
picion that  the  disease  begins  at  the  periphery  of  the  choroid,  and 
only  in  its  later  course  attacks  the  portion  most  concerned  in 
vision.  If  this  is  the  result,  the  term  choroiditis  diffusa  is  justi- 
fiable. 

Fresh  patches  are  round,  sharply  defined,  small  (much  smaller 
than  the  disc),  yellowish-red  and  lighter  in  color  than  the  fundus. 
A  histological  examination  shows  them  to  be  flattish  nodules,  con- 
sisting of  lymphoid  cells,  lying  in  the  innermost  layers  of  the 
choroid ;  the  adjacent  pigment  epithelial  cells  of  the  retina  are 
bleached.  There  is,  besides  this,  a  diffuse  infiltration  of  lymphoid 
cells,  particularly  along  the  vessels,  in  consequence  of  which  they 


292  DISEASES    OF   THE    MIDDLE   TUNIC    OF   THE    EYE. 

appear  to  the  ophthalmoscope  as  yellowish-white  striae.  If  the 
disease  advances  the  patches  become  larger,  coalesce,  and  form 
irregularly  shaped  figures.  Still  further  on,  the  exudate  becomes 
absorbed,  but  the  pigment  epithelium  of  the  retina  hypertrophies, 
recognizable  ophthalmoscopically  by  the  appearance  of  irregular, 
jagged  black  blotches.  In  favorable  cases  these  are  the  only  re- 
maining signs  of  cured  choroiditis ;  in  the  majority  of  cases,  how- 
ever, the  choroidal  tissue  atrophies  as  the  exudate  is  absorbed, 
while  new  connective  tissue  may  or  may  not  be  formed.  If  it  is, 
it  may  be  detected  ophthalmoscopically  as  yellowish  or  whitish 
patches,  either  because  the  sclera  has  become  visible,  or  because 


Fig.  106. — Ophthalmoscopic  Appearance  in  Choroiditis  Disseminata.    (After  Jaeger.) 

the  cicatrix  reflects  the  light  powerfully.  White,  irregular,  black- 
bordered  patches  are  therefore  local  evidence  of  a  choroiditis  {Fig. 
106)  that  has  run  its  course. 

The  image  is  usually  very  easily  seen,  since  vitreous  opacities  are 
rare  in  choroiditis  disseminata.  The  optic  nerve  is  generally 
affected,  as  may  be  recognized  by  the  moderate  redness  and  cloudi- 
ness of  the  disc. 

There  is  no  relation  between  the  amount  of  visual  disturbance 
and  the  changes  noticeable  in  the  fundus.  Vision  may  be  nearly 
normal,  although  the  fundus  is  as  variegated  as  a  map  of  Europe. 
Of  course,  vision  must  suffer  in  the  end  if  the  macula  lutea  becomes 


CHOROIDITIS    CIRCUMSCRIPTA    CENTRALIS.  293 

involved  and  if  the  optic  nerve  atrophies ;  it  is  then  reduced  to 
counting  fingers,  or  it  may  be  quite  destroyed.  The  same  is  true  of 
the  visual  field  ;  some  irregularity  in  it  and  an  occasional  scotoma 
may  always  be  found,  but  it  should  never  be  asserted  that  a  chart 
of  the  visual  field  will  correspond  to  the  ophthalmoscopic  image. 
Nor  must  it  be  forgotten  that  the  "  dark  spot  "  represents  physio- 
logically an  absence  of  function  in  a  certain  retinal  area,  while  an 
ophthalmoscopic  patch  is  only  a  pathological  choroidal  area.  The 
disease  attacks  both  eyes,  as  a  rule.  Its  course  is  unusually  chronic 
and  years  may  lie  between  the  first  visual  disturbance  and  the  final 
blindness.  There  may  be  prolonged  intermissions  or  it  may  even 
come  to  a  permanent  standstill.  The  atrophy  of  the  choroid  some- 
times occasions  opacities  in  the  lens,  nourished,  as  it  is,  by  the 
uvea  (  see  Causes  of  Cataract). 

Choroiditis  areolaris  [Foentet-)  is  a  rare  form  of  the  disease.  It  begins  not  with 
light  but  with  black  patches  and  small,  jagged  pigment  blotches.  These  become  larger 
and  rounder,  their  centers  increase  from  yellowish,  later  whitish  dots,  till  they  are 
changed  gradually  into  whitish  blotches  with  black  edges.  Areolar  choroiditis  is,  in 
another  way,  distinguishable  for  the  disseminated  form  ;  the  former  begins  near  the  pos- 
terior pole  and  therefore  endangers  central  vision  much  more  directly  than  does  the  lat- 
ter. In  spite  of  this  the  physician  is  often  nonplussed  in  finding  a  visual  acuity  that, 
seems  to  defy  even  the  coarsest  changes  near  the  fovea  centralis !  Nevertheless  this 
favorable  condition,  even  after  thirty  years'  duration,  may  end  with  a  sudden  and  rapidly 
increasing  impairment  of  vision. 

Choroiditis  circumscripta  centralis  (chororetinitis  centralis)  is  soon  detected  on 
account  of  its  location  at  the  macula  lutea.  The  patient  says  he  sees  a  gray  spot,  "  posi- 
tive scotoma,"  which  is  always  exactly  at  the  place  he  wishes  to  look  at  most  carefully, 
and  that  when  reading  the  lines  appear  bent  [inetamorphopsia).  As  the  disease  progresses 
the  positive  changes  to  a  negative  scotoma,  that  is,  the  patient  has  a  defect  in  his  visual 
field,  although  it  does  not  seem  to  be  traceable  to  a  black  patch.  Ophthalmoscopically 
the  changes  are  similar  to  those  already  described,  but  they  are  found  solely  at  the  macula 
lutea,  the  rest  of  the  fundus  being  normal. 

Exudative  inflammation  of  the  choroid  results  from  some  general 
disease.  Unfortunately  it  is  not  always  possible  to  find  out  this 
general  disease,  even  by  most  careful  investigation.  In  a  propor- 
tion of  cases  syphilis  is  at  the  bottom  of  it  and  should  be  especially 
suspected  if  vitreous  opacities  are  present  or  if  a  parenchymatous 
keratitis  has  preceded  it.  Tuberculosis,  scrofula,  and  chlorosis 
have  been  reported  as  causes. 

Treatment  must  be  directed  against  any  discoverable  cause. 
Even  if  nothing  is  discovered,  many  ophthalmologists  insist  that 
inunctions  (of  mercury)  should  be  tried.     I  pursue  this  course  only 


294  DISEASES    OF   THE    MIDDLE   TUNIC    OF    THE    EYE. 

when  the  patient  is  strong  and  the  disease  recent.  In  other  cases 
I  restrict  my  treatment  to  diaphoresis,  iodid  of  potassium,  and  rest 
for  the  eyes  from  work  and  bright  light  by  smoked  glasses.  Such 
treatment  often  improves  the  visual  acuity  without  effecting  any 
change  in  the  appearance  of  the  fundus.  Confinement  in  a  dark 
room  is  unnecessary. 

3.  CHORORETINITIS  SYPHILITICA  (FOERSTER). 
This  term  is  applied  to  a  disease  well  recognized  clinically, 
although  it  has  not  yet  been  sufficiently  studied  pathologically.  It 
is  undoubtedly  due  to  syphilis,  and  is  often  preceded  by  a  mild 
iritis,  which  distinguishes  it  from  the  various  forms  of  exudative 
choroiditis.  The  patient  becomes  aware  of  it  by  the  subjective 
symptoms  (bright  spots  and  disks,  flickerings)  and  by  the  reduction 
in  visual  acuity.  The  objective  signs,  at  least  in  the  commencement 
of  the  disease,  are  hardly  appreciable,  the  most  important  being  an 
extremely  fine  dust-like  haziness  of  the  vitreous,  which  somewhat 
obscures  the  view  of  the  optic  disc  and  retinal  vessels,  and  may  be 
best  seen  with  the  pupil  dilated  by  using  weak  illumination  and  a 
plane  mirror.  Groups  of  light  red  or  whitish  patches  may  be  also 
detected  in  the  macula  lutea.  At  the  height  of  the  disease  the 
vitreous  opacities  may  be  very  abundant.  The  consequences  of 
the  disease  are  distinct  changes  in  the  fundus,  consisting  chiefly  of 
variously  shaped  black  pigment  patches,  and  of  a  grayish-yellow 
discoloration  of  the  optic  disc  (atrophy).  The  subjective  examina- 
tion shows  much  more  positive  evidence  of  disturbance,  the  visual 
acuity  being  reduced  to  |-  or  ^,  or  even  to  j^  to  y^^,  without  any 
more  noticeable  changes  in  the  fundus.  By  testing  with  groups  of 
parallel  lines  it  can  be  demonstrated  that  the  patient  thinks  that  the 
lines  are  bent  toward  the  point  of  fixation — metamorpJiopsia.  The 
range  of  accommodation  is  reduced,  although  this  can  scarcely  be 
detected  if  vision  is  very  poor.  The  most  characteristic  signs  are 
night-blindness  (see  Hemeralopia)  and  ctrcumscribed  scotomata  in 
the  field  of  vision.  This  latter  expression  indicates  that  the  fovea 
centralis  and  the  periphery  of  the  retina  both  functionate  com- 
paratively normally ;  but  that  the  portion  lying  between  the  center 
and  the  circumference  has  areas  of  greater  or  less  functional  weak- 
ness, which  may  occasionally  coalesce  to  form  a  semicircle 
or  an  entire  ring  {Fig.  loj).  In  unfavorable  cases  of  the  dis- 
ease   vision    may    become    so    changed    that    only    a    few    bright 


CHOROIDITIS    SUPPUJJATIVA.  295 

areas  remain  in  the  otherwise  darkened   field   of  vision — "  Visus 
reticulatus." 

Treatment  is  happily  of  great  service  in  the  disease.  An  im- 
pressive course  of  mercurial  inunction,  with  complete  rest  to  the 
eyes,  may  bring  about  improvement  after  several  weeks,  or  may 
even  effect  a  cure.     Relapses  are  not  unusual. 

4.  CHOROIDITIS  SUPPURATIVA. 
This  is  one  of  the  eye's  worst  enemies,  for  it  may  take  but  a  day 
or  so  to  destroy  the  eye,  while  weeks  and  months  may  elapse  be- 
fore the  eye,  or  what  atrophied  fragment  of  it  is  left,  becomes  free 
from  pain.  The  disease  begins  with  hemorrhage  into  the  retina 
and  choroid  ;  then  follows  an  abundant  collection  of  pus  cells,  which 


Fig.  107. — Field  of  Vision  in  Choroiditis  Syphilitica.     {After  ll-libranti.) 
The  darkened  areas  are  defects  in  the  field. 

lie  at  first  in  the  innermost  layers  of  the  choroid  and  along  the  ves- 
sels, but  which  soon  invade  the  entire  choroid,  retina,  and  vitreous. 
Externally  the  eye  has  the  following  appearance :  the  lids  and 
conjunctiva  are  red  and  swollen,  and  throw  off  a  mass  of  purulent 
mucus ;  the  cornea  is  somewhat  hazy,  its  surface  lusterless;  in  the 
anterior  chamber  there  is  found  pus — hypopyon  ;  the  iris  is  dis- 
colored, swollen,  and  in  places  adherent  to  the  lens ;  the  pupil  ap- 
pears yellowish,  the  light  entering  it  being  reflected  from  the  pus- 
infiltrated  vitreous  ;  the  eyeball  is  hard.  The  patient  complains  of 
great  pain  in  the  eye  and  forehead  ;  he  is  blind  in  the  affected  eye ; 
he  has  fever,  and  general  malaise.  This  description  may  apply  to 
the  disease  at  its  height,  and  as  the  inflammation  subsides,  in  the 
course  of  weeks,  a  cure  may  be  effected — not  a  cure  of  the  blind- 


296  DISEASES    OF   TH^  MIDDLE    TUNIC    OF   THE    EYE. 

ness,  however,  but  only  of  the  inflammation,  for  it  is  very  rare  that 
any  visual  perception  is  preserved. 

This  condition  is  not  always  applicable  to  the  height  of  the  dis- 
ease. Fever  may  increase,  pain  may  become  unbearable,  and  sup- 
puration may  extend  beyond  the  eyeball.  Then  exophthalmos  is 
produced,  the  eye  becomes  immovable,  and  panophthalmitis  is 
inevitable.  The  eye  becomes  an  abscess  cavity,  but  it  is  a  matter 
of  much  time  and  agony  before  the  sclera  is  perforated.  The  pus 
does  finally  escape,  however,  the  pain  subsides,  the  eye  atrophies, 
and  the  patient  gets  well. 

Purulent  inflammation  of  the  choroid,  with  its  daughter,  pan- 
ophthalmitis, is  caused  by  the  entrance  of  germs  (staphylococci, 
streptococci,  bacilli).  In  some  cases  they  are  brought  to  the  eye 
from  other  parts  by  the  circulation,  and,  lodging  in  the  choroidal 
capillaries,  they  form  septic  emboli.^ 

This  occurs  occasionally  in  puerperal  fever,  pyemia,  and  numer- 
ous other  severe  infectious  diseases,  but  since  patients  are  apt  to 
die  from  the  principal  disease,  the  eye  trouble  plays  but  a  subordi- 
nate part.  In  other  cases  germs  enter  the  eye  from  without,  either 
during  operations  or  from  injuries,  or  are  easily  carried  by  foreign 
bodies  that  penetrate  to  the  interior.  Thin  cicatrices  may  admit 
the  passage  of  these  germs. 

Treatment  can  do  no  more  than  to  quiet  pain  by  narcotics,  or  by 
the  local  use  of  atropin  and  hot  compresses ;  or  to  end  matters  by 
an  operation,  consisting  of  an  incision  between  the  tendons  of  the 
external  and  inferior  recti.  Exenteration  of  the  eyeball  is  surer 
still.  Enucleation,  the  most  radical  remedy,  was  formerly  avoided 
in  panophthalmitis,  because  death  from  meningitis  so  often  resulted  ; 
but,  thanks  to  antisepsis,  hundreds  of  cases  are  now  treated  with 
the  best  success  by  enucleation. 

Choroiditis  suppurativa  chronica  may  run  its  course  without  any  signs  visible 
externally,  but  the  ophthalmoscope  detects  the  effect  of  the  disease  as  a  yellowish  mass, 
consisting  chiefly  of  pus  cells,  which  the  choroid  throws  out  either  behind  the  retina  or 
into  the  vitreous.     It  may  be  comprised  with  glioma  retinte  [q.  7'.). 

5.  TUBERCULOSIS  OF  THE  CHOROID. 
This  appears  in  two  different  forms.     Sometimes  it  is  associated  with  general  miliary 
tuberculosis,  but  as  this  is  a  severe  and  incurable  disease  the  patient  seldom  comes  to  the 
ophthalmologist,  and  ophthalmoscopic  examination  is  made  at  the  suggestion  of  the  attend- 


^  Hence  the  name  choroiditis  embolica,  septica,  vietastatica. 


SARCOMA    OF   THE    CHOROID.  297 

ing  physician,  because  the  detection  of  the  choroidal  nodules  of  tubercle  removes  all  doubt 
as  to  the  nature  of  the  systemic  trouble,  if  there  is  any  remaining  uncertainty  in  distinguish- 
ing between  tuberculosis  and  typhoid.  The  tubercles  are  found  in  the  inner  layers  of 
the  choroid,  near  the  posterior  pole  ;  with  the  ophthalmoscope  they  are  seen  to  be  small, 
round  or  egg-shaped,  whitish-yellow  or  white  spots,  the  smaller  ones  being  indistinctly, 
the  larger  ones  sharply  outlined,  some  having  a  pigmented  edge.  Those  which  happen 
to  be  crossed  by  retinal  vessels  are  very  clearly  seen  to  protrude  toward  the  center  of  the 
eye.  The  number  of  nodules  visible  with  the  ophthalmoscope  is  probably  only  one-tenth 
of  those  actually  present,  as  the  others  are  doubtless  too  small  or  too  deeply  imbedded  to 
produce  any  atrophy  of  the  retinal  pigment  epithelium.  Their  rapid  development  or 
growth  is  remarkable  ;  new  nodules  may  become  visible  within  twenty-four  hours.  They 
have  the  histological  structure  of  miliary  tubercles,  with  the  additional  characteristic  that  ' 
the  (comparatively  infrequent)  giant  cells  contain  pigment,  a  condition  that  was  at  one 
time  supposed  to  belong  e.xclusively  to  miliary  tubercles  of  the  lung.  The  choroid 
between  the  tubercular  nodules  is  hyperemia  and  diffusely  infiltrated  with  round  cells. 

The  second  form  is  of  more  interest  to  the  ophthalmologist.  It  is  evidenced  by  the  de- 
velopment of  a  tumor  (spheroidal  tubercle)  which  causes  detachment  of  the  retina  and 
blindness,  and  which  may  set  up  inflammation  of  the  eye,  recognizable  by  the  posterior 
synechiae,  vitreous  opacities,  and  pain.  Such  cases  have  been  reported  in  persons  who  are 
apparently  free  from  other  signs  of  tuberculosis ;  nevertheless,  in  most  of  them  there  was 
developed,  after  a  longer  or  shorter  interval,  a  tuberculosis  of  the  cerebral  membranes  or 
of  the  lungs,  which  finally  resulted  in  the  patient's  death.  If  the  fundus  is  still  visible, 
the  diagnosis  must  be  made  between  tubercle  and  sarcoma.  The  youth  of  the  patient, 
the  detection  of  other  foci  of  tuberculosis,  swollen  lymph  glands,  bright  color  of  the 
tumor,  and  the  presence  of  smaller  nodules  around  its  base — all  indicate  tuberculosis.  It 
makes  little  difference  to  the  patient,  however,  what  the  diagnosis  may  be  ;  in  both  cases 
enucleation  is  unconditionally  indicated,  for  the  tubercular  nodules  not  only  grow  toward 
the  vitreous  but  they  penetrate  the  sclera,  attack  the  cellular  tissue  of  the  orbit,  and  may 
even  spread  backward  along  the  optic  nerve.  The  eye  is  lost  and  life  endangered 
thereby. 

6.  SARCOMA  OF  THE  CHOROID. 

The  disease  is  very  rare ;  it  appears  but  5  to  7  times  in  10,000 
cases  of  eye  trouble.  The  tumor  develops  slowly  at  first,  but 
later  on  it  involves  the  surrounding  tissue  with  great  rapidity.  This 
tumor  consists  of  a  delicate,  connective-tissue  framework,  filled 
with  numerous  large,  round  or  jagged  or  spindle-shaped  cells, 
which  look  like  embryonic  cells,  and  may  in  the  same  way  develop 
into  the  different  forms  of  the  connective-tissue  group.  In  about 
90  per  cent,  of  cases  the  sarcoma  cells  contain  pigment  granules, 
and  the  tumor  is  called  a  melanosarcoma,  in  contradistinction  to 
the  leukosarcoma,  whose  cells  havfe  no  pigment.  Probably  a  sar- 
coma arises  always  in  the  layer  of  the  larger  vessels.  The  causes 
are  obscure. 

Knapp  and  Fuchs  have  divided  the  course  of  the  disease  into 
four  stages.  The  first  stage  is  that  of  freedom  from  irritation,  the 
20 


298 


DISEASES    OF   THE    MIDDLE   TUNIC    OF   THE    EYE. 


only  subjective  symptom  being  disturbance  of  vision.  If,  as  is  usu- 
ally the  case,  the  sarcoma  grows  near  the  posterior  pole  {Fig.  108), 
the  disturbance  consists  of  reduction  in  visual  acuity,  lessened  re- 
fractive power,  myopia  becoming  hyperopia,  for  example,  and  dis- 
tortion of  images.  If  the  sarcoma  is  at  the  periphery,  the  visual 
disturbance  is  detectable  as  a  dark  spot  (scotoma).  Some  patients 
do  not  notice  this  gradual  approach  of  visual  disturbance,  and  the 
physician  does  not,  therefore,  have  occasion  to  make  an  examina- 
tion during  the  first  stage.  The  tumor  may  be  objectively  detected 
by  the  ophthalmoscope,  especially  if  a  detachment  of  the  retina 
{q.  v.),  with  nodular  form  and  abrupt  sides,  arouses  the  suspicion  of 
an  underlying  tumor.  In  many  cases  the  tumor  appears  yellow- 
ish-red or  brown,  covered  with  a  fine  network  of  blood-vessels, 
which  shimmer  through  the  still  transparent  retina.  If  a  fluid 
exudate  is  deposited  between  tumor  and  retina,  this  characteristic 
picture  disappears,  and  the  ophthalmoscope 
discovers  nothing  but  the  retinal  detach- 
ment. The  first  stage  varies  from  six  months 
to  four  years. 

The  second  stage  is  that  of  inflammation. 
Severe  pain  is  the  symptom  most  noticed 
by  the  patient.  In  the  majority  of  cases 
this  pain  is  caused  by  the  increased  tension 
produced  by  the  tumor ;  this  may,  therefore, 
be  called  the  glaucomatous  stage.  In  the 
minority  of  cases  the  pain  is  caused  by  irido- 
cyclitis {p.  286).  Visual  acuity  declines  as 
the  pain  continues,  until  total  blindness  is  reached,  since  increased 
tension  makes  the  retinal  detachment  complete.  The  diagnosis  of 
the  tumor  may  be  impossible  in  this  stage,  owing  to  cloudiness  of 
the  refractive  media.  This  stage  is  shorter  than  the  first,  lasting 
about  one  year  on  the  average. 

The  third  stage  is  marked  by  the  perforation  of  the  sclera  by  the 
unrestrainable  growth  of  the  tumor.  The  perforation  is  announced 
by  the  appearance  of  dark,  hard  nodules  on  the  sclera  and  is  grate- 
fully welcomed  by  the  patient  on  account  of  the  relief  from  pain 
which  it  brings.  If  perforation  occurs  at  some  posterior  portion 
not  accessible  to  the  observer,  he  is  aware  of  the  condition  only 
when  exophthalmos  and  restriction  in  eye  movements  are  produced 
by  the  increase  in  the  tumor's  size.     It  now  makes  rapid  strides  ; 


Fig.  108. — Sarcoma  of  the 
Chokoiu.  (After  Pagen- 
stecher  and  Centh.) 


SARCOMA    OF   THE    CHOROID.  299 

the  eye  becomes  a  mere  tumor  mass  protruding  between  the  lids ; 
there  is  pain,  hemorrhage,  and  abundant  secretion,  so  that  the 
patient  may  die  of  exhaustion  even  if  no  metastasis  has  occurred. 

Tlic  fourtJi  stage,  and  the  last,  is  the  stage  of  metastasis,  in  which 
elements  of  the  sarcoma  are  carried  by  the  circulation  most  often 
to  the  lung  and  liver,  where  new  tumors  are  developed  which  lead 
to  the  inevitable  death  of  the  patient. 

From  what  has  been  said  it  will  be  seen  that  the  diagnosis  of 
the  disease  is  sometimes  easy,  sometimes  difficult,  sometimes  im- 
possible. An  accurate  history  of  the  patient  will  often  simplify 
matters.  Confusion  with  retinal  or  choroidal  detachments,  with 
primary  (acute)  glaucoma,  and  with  spheroid  tubercle  is  most 
likely  to  happen.  Increased  tension  caused  by  sarcoma  is  absent 
in  simple  retinal  or  choroidal  detachment ;  retinal  detachment  is 
absent  in  primary  glaucoma,  and  it  may  be  added  that  sarcoma  is 
almost  without  exception  unilateral,  while  on  the  contrary  primary 
glaucoma,  which  has  already  caused  blindness,  will  most  probably 
show  some  traces  of  its  presence  in  the  other  eye. 

The  prognosis  is  fatal  if  no  treatment  be  instituted ;  always 
unfavorable  even  if  treatment  is  begun  early. 

Treatment  must,  of  course,  proceed  to  the  radical  removal  of 
all  diseased  tissue ;  the  eye  must  be  enucleated  in  the  first  and 
second  stage,  or  the  entire  orbit  must  be  cleaned  out  in  the  third 
stage.  Experience  has  shown  that  the  danger  of  local  relapse  is 
practically  nothing  if  the  eye  is  removed  during  the  first  stage  of 
the  disease ;  that  it  is  still  neglectable  if  the  operation  is  per- 
formed during  the  second  stage,  but  that  it  is  very  threatening  (22 
per  cent.)  if  delayed  till  the  third  stage.  It  should  by  no  means 
be  concluded  from  this  that  an  early  operation  insures  a  bright 
future  for  the  patient,  for,  although  local  relapse  is  avoided,  metas- 
tasis is  still  to  be  feared.  Indeed,  Fuchs  declares  that  the  danger 
of  infection  by  metastasis  is  not  essentially  influenced  by  the  time 
at  which  the  operation  is  performed.  It  may  be  imagined  that 
small  sarcomatous  elements,  retained  within  the  closed  capsule  of 
the  eye,  have  passed  into  the  circulation.  The  reverse  is  also  true, 
that  the  germs  of  malignant  tumors — say  of  the  lacteal  glands — 
may  be  carried  to  the  choroid  by  the  blood.  Numerous  cases  have 
recently  been  reported  of  metastatic  carcinoma  of  the  choroid. 


300 


DISEASES    OF   THE    MIDDLE   TUNIC    OF   THE    EYE. 


7.  RUPTURE  OF  THE  CHOROID. 
Ruptures  (lacerations)  of  the  choroid  are  very  common ;  v. 
Wecker  says  they  occur  regularly  after  all  injuries  to  the  eye 
with  a  dull  weapon.  The  medical  significance  is,  however,  slight, 
since  the  accident  always  takes  place  in  eyes  severely  injured  in 
other  ways,  and  cannot  therefore  be  immediately  recognized,  on 
account  of  hemorrhage  in  the  vitreous  and  other  causes  of  opacity. 
If  the  vitreous  becomes  transparent  again,  a  recent  rupture  appears 
as  a  yellowish,  blood-specked  stripe,  lying  usually  between  the  macula 

lutea  and  the  papilla,  and  embracing 
the  latter  with  a  gentle  curve.  Its 
location  at  the  posterior  pole  is 
ascribed  to  the  fact  that  at  this 
place  the  choroid  is  bound  down 
to  the  sclera  by  the  entering  ciliary 
vessels,  and  is  not,  therefore,  so 
easily  displaceable  as  the  portion 
further  forward.  Old  choroidal 
ruptures  are  lighter  and  whiter, 
and  are  bordered  with  black  pig- 
ment {Fig.  logi).  Small  ruptures 
may  become  completely  united. 
The  effects  of  a  rupture  on  the 
visual  power  depend  essentially 
upon  its  involvement  of  the  retina  and  especially  upon  the  area 
affected  :  the  nearer  to  the  macula  lutea  the  graver  the  consequences 
to  vision. 

Treatment. — Atropin  and  rest. 


Fig.  109. — Two  Ruptures  in  the  Choroid. 

(After  Kna/>p.) 
The  retinal  vessels  pass  unbroken  across  the 

rupture.     The  dark  spot  to   the  right  is  a 

hemorrhage. 


8.  DETACHMENT  OF  THE  CHOROID. 

A  detachment  of  the  choroid  is  recognizable  ophthalraoscopically  as  a  roundish,  brown, 
smooth  tumor  near  the  equator  of  the  eye.  The  retina  above  it  is  faintly  clouded,  but 
does  not,  as  a  rule,  prevent  the  true  choroidal  vessels  from  being  visible  through  it. 
While  detachment  of  the  retina  [q.  v.)  is  detected  by  a  trembling  or  shivering  move- 
ment accompanying  a  movement  of  the  eye,  this  is  not  the  case  in  detachment  of  the 
choroid.  Again,  to  distinguish  the  latter  from  a  tumor,  the  eye's  tension  should  be  taken  ; 
in  tumors  this  is  usually  increased,  while  in  choroidal  (and  retinal)  detachment  it  is 
diminished.  Choroidal  detachments  may  reunite  completely.  Many  of  the  hitherto 
reported  cases  have  been  due  to  a  loss  of  vitreous  during  cataract  operations ;  others 
occurred  without  antecedent  injury. 

Treatment. — Rest. 


DISEASES    OF   THE    RETINA    AND    OPTIC    NERVE.  3OI 

9.  CONGENITAL  DEFECTS  IN  THE  CHOROID  (Coloboma  Choroide^). 
These  appear  in  the  choroid  as  well  as  in  the  iris  ;  their  ophthalmoscopic  image  is 
very  characteristic.  On  the  floor  of  the  fundus,  below  the  disc,  at  a  distance  of  about 
three  to  four  times  its  diameter,  there  is  seen  a  large,  whitish  or  bluish,  glistening  area, 
irregular  in  shape,  sometimes  flap-like,  sometimes  oval,  with  the  long  axis  in  the  direc- 
tion of  one  of  the  eye's  principal  meridians.  Its  edges  are  strewn  with  pigment.  Retinal 
(as  well  as  scleral)  blood-vessels  pass  across  it.  The  retina  above  a  choroidal  coloboma 
is  essentially  modified  and  degenerated,  and  can,  therefore,  functionate  only  imperfectly. 
Cases  have  been  described  in  which  a  choroidal  coloboma  had  no  scotoma  in  the  visual 

field  corresponding  to  it.     Visual  acuity  may  be  normal, in   one   case   reported   by 

Saemisch ;  but,  besides  the  coloboma,  there  may  be  other  anomalies  present  to  reduce 
the  eye's  functionary  power. 

10.  NODULES  (Warts). 

Thickening  of  the  lamina  vitrea  of  the  choroid  near  the  equator  is  a  not  unusual 
occurrence  in  elderly  jiersons.  They  form  nodule-like  prominences,  having  a  concentric- 
ally laminated  structure  and  a  meshed  covering  of  pigment  epithelium.  Ophthalmoscopic- 
ally,  they  appear  as  small,  round  or  egg-shaped,  or  irregularly  bordered,  bright  patches, 
that  reflect  light  strongly — the  wavy  reflex.  As  they  lie  near  the  periphery  they  seldom 
cause  visual  disturbance,  and  are,  as  a  rule,  discovered  only  by  accident.  Occasionally 
they  are  found  near  the  posterior  pole,  and  they  then  affect  the  visual  power  to  some 
extent. 


DISEASES  OF  THE  RETINA  AND  OPTIC  NERVE. 

INTRODUCTION. 

The  third  and  innermost  tunic  of  the  eye  is  called  the  retina.  It  covers  the  inner 
surface  of  the  choroid  as  far  as  the  pupillary  border.  It  is  closely  attached  to  the  ciliary 
body  and  iris  and  is  adherent  at  the  aperture  of  entrance  of  the  optic  nerve, but  it  is  only 
loosely  attached  to  the  choroid.     There  are  to  be  distinguished : — 

(1)  An  optical, 

(2)  A  ciliary,  apd 

(3)  An  iritic  portion. 

The  optical  portion  is  the  only  one  that  plays  any  part  in  vision  or  that  need  be  dis- 
cussed here.  Its  structure  is  extremely  complex.  In  sectionat  the  "pars  optica  retinae  " 
[Fig.  no)  there  are  seen  ten  layers  lying  parallel  to  the  wall  of  the  eye.  There  are  also 
some  fibers  perpendicular  to  the  wall  of  the  eye,  the  supporting  fibers  of  Mueller,  a  con- 
nective-tissue framework  in  which  the  nervous  elements  are  retained.  The  function  of 
each  layer  in  vision  is  but  little  understood.  There  is  no  doubt  that  the  rods  and  cones 
are  sensitive  to  light,  that  is,  by  their  function  the  physical  phenomenon  of  ether  oscilla- 
tions becomes  a  physiological  process. 

It  was  at  one  time  supposed  that  the  stimulation  produced  by  light  in  a  rod  or  cone 
was  passed  on  through  the  nerve-element  of  the  retina  and  through  a  fiber  of  the  optic 
nerve  to  the  brain  cortex — the  abode  of  consciousness, — just  as  a  message  is  sent  along 
a  telegraph  wire. 

Later  histological  investigation  has  shown  that  the  process  is  by  no  means  so  simple. 
A  glance  at  Fig.  ///  shows  that  the  visual  cells  (rods  and  cones)  are  not  at  all  in  direct 


302 


DISEASES    OF    THE    RETINA    AND    OPTIC    NERVE. 


or  uninterrupted  connection  with  the  brain.  Light  stimulation,  which  has  affected  the 
single  cone  in  Fig.  iii,  is  modified  as  soon  as  it  reaches  the  external  reticular  layer. 
Here  as  well  as  in  the  inner  granular  layer  there  are  cells  of  a  ganglionic  nature  whose 
roots  are  buried  in  the  confused  mass  of  the  external  reticular  layer'  and  between  the 
nuclei  of  the  visual  cells,  and  whose  axis-cylinders  lead  to  the  confused  mass  of  the  inter- 
nal reticular  layer,  ending  as  terminal  branches,  or  continuing  as  cell  b  directly  into  the 
nerve-fiber  layer  and  the  optic  nerve  itself.  Stimulation,  which  has  arrived  at  the  con- 
fused mass  of  the  internal  reticular  layer,  experiences  here  a  second  modification. 
Stimulation  here  affects  a  second  "  neuron,"  ^  a  ganglion-cell  having  its  terminal 
branch  in  the  external  corpus  geniculatum  of  the  brain  {Fig.  iij).  A  third  modification 
is  effected  here,  other  ganglion-cells  receiving  the  stimulation  and  conducting  it  through 


Tt^Tnent  e/ji/Jieliujn^. 


Xayer  ofJUods ) 
an/t  Con&s     ] 


Ix 


E3:t.ernaZ  hjruting  memdrane.  3 
ExiernaloranMlar  layer         4- 

£xlernaZ  re&cuZ/zr  layer       S 

jTvlemaZ  yranulur  layer    6 
^- Fibers  of  Jftilier. 

jTtterruil  JvticuICLr  layer      ' 


Gan^lum^  Cell  layer 


8 


Mrre  fiber.f  layer  9 

JjiiernaZ'  Iz^ruiiriff  nvetnirane.  10 

Fig.  iio. — Retina,  with  its  Nervous,  Epithelial,  and  Connective-Tissue   Elements. 
Somewhat  Diagrammatic     {After  Schuitze.)  ^ 

the  "  optic  radiation  "  to  the  terminal  branches  in  the  cerebral  cortex  of  the  occipital  lobe. 
The  ganglion-cells  of  the  cortex  convert  it  into  a  visual  perception. 

Let  us  examine  again  the  innermost  or  nerve-fiber  layer  of  the  retina.  It  consists 
chiefly  of  axis-cylinders  having  their  ganglion-cells  in  the  retina,  their  terminal  branches 
in  the  external  corpus  geniculatum  ;  they  are  therefore  assumed  to  be  centripetal  conduct- 


1  The  morphological  unity  is  expressed  as  ganglion-cell,  axis-cyjinder,  terminal  branch. 

*  Referring  to  (5)  external  reticular  layer,  Stoehr's  latest  investigations  show  it  to  con- 
sist really  of  two  layers,  [a)  Henle's  fibrous  layer,  {l>)  essentially  reticulated  layer.  For- 
merly the  fibrous  layer  had  been  recognized  only  at  the  macula  lutea,  where  it  is  particu- 
larly broad. 


INTRODUCTION. 


303 


ing  fibers.  Some  axis-cylinders,  however,  have  their  ganglion-cells  in  the  corpus  geni- 
culatum  and  the  terminal  branches  in  the  retina  (inner  nuclear  layer) ;  they  are  therefore 
assumed  by  many  investigators  to  be  centrifugal  fibers.  The  fibers  of  the  nerve-fiber 
layer  converge  toward  the  foramen  sclerce,  where  they  are  here  collected  together  to  form 
the  head  (beginning)  of  the  optic  nerve  (TvV.  jo).  From  its  exit  from  the  eyeball  to  its 
entrance  into  the  canalis  opticus  the  nerve  measures  28  to  2g  mm.  Osving  to  this  con- 
siderable length  the  nerve  is  not  straight,  but  has  a  rather  S-shaped  curve,  and  is,  there- 
fore, capable  of  being  stretched  quite  an  interval  without  restricting  the  eyeball  in  any 
of  its  rotations.  The  nefve  is  covered  by  three  sheaths,  the  closely  approximated  and 
adherent  pial  sheath,  and  the  looser  dural  sheath  {Fig.  jo) ;  between  these  two  lies  a 
lymph  space,  separated  into  two  compartments  by  the  extremely  thin  membrane,  the 
arachnoid  sheath.  The  optic  nerve  itself  is  composed  of  bundles  of  nerve-fibers  varying 
in  thickness  ;  it  is  so  richly  supplied  with  egg-shaped  nuclei  that  they  have  been  taken 
for  evidence  of  inflammatory  cell  infiltration.  Krause  estimates  the  number  of  nerve- 
fibers  at  "400,000  coarse  and  fine,  with  about  the  same  number  of  very  finest  fibers." 
We  may  assume  that  they  are  very  unevenly  distributed  over  the  retina.  The  region 
between  macula  and  disc  is  most  abundantly 
supplied,  the  nerve-fibers  destined  for  it  be- 
ing designated  as  the  papillomacular  bundle. 
This  lies  close  behind  the  eyeball  at  the  tem- 
poral side  of  the  optic  nerve,  but  further 
backward  it  passes  to  the  center  of  the 
nerve. 

It  is  an  important  question  whether  the 
optic  nerve  of  one  eye  proceeds  only  to  the 
cortex  of  the  opposite  half  of  the  cerebrum, 
or  whether  it  proceeds  to  the  half  of  the  same 
side  as  well ;  in  other  words,  whether  the 
optic  nerves  of  the  two  eyes  experience  a 
complete  or  only  a  partial  decussation  at  the 
chiasm.  It  is  a  general  law  that  nerves 
decussate  in  passing  from  their  centers  to 
their  peripheral  terminations.  From  the 
smallest    vertebrates   up    to   man    the    right 

brain  perceives  that  which  stimulates  the  left  half  of  the  body  ;  and  the  right  side 
of  the  body  obeys  the  nervous  impulse  that  originates  in  the  left  brain.  This  law 
is  applicable  also  to  the  visual  sense.  In  fishes,  for  example,  whose  eyes  are  on 
the  side  of  the  body,  each  possessing  an  absolutely  independent  field  of  vision,  the 
decussation  of  the  optic  nerves  is  complete ;  this  may  be  easily  demonstrated  in  the 
herring,  where  there  is  no  intermixture  of  fibers,  but  in  which  one  optic  ners'e  passes 
in  its  entirety  through  a  slit  in  the  other.  The  matter  becomes  more  complicated  in 
the  higher  vertebrates,  where  the  eyes  are  closer  toward  the  front  of  the  body,  the 
necessity  for  a  right-  and  left-sided  visual  apparatus  being  thus  lost.  If  we  imagine  a 
median  section  through  a  body  of  the  higher  vertebrate,  it  is  obvious  that  the  left  eye  will 
still  see  a  large  proportion  of  the  objects  lying  to  the  right  of  this  plane,  and  fire  versa  ; 
in  other  words,  in  the  higher  vertebrates  the  visual  fields  of  the  two  eyes  coincide  to  a 
greater  or  less  degree.  If,  now,  a  complete  decussation  of  the  optic  nerves  took  place, 
the  right  brain  would  nevertheless  still  see  a  portion  of  the  outer  world  at  the  right.  As 
a  matter  of  fact  this  is  not  the  case.  Experience  has  shown  that  if  the  right  brain  loses 
its  function — say  from  a  hemorrhage — the  left  eye  is  not  blinded,  but  that  that  portion  of 


Jiod  JVucleua 
Sxiey/iiU  reticular  iayyer. 

b 

Injier  amnu&uf  layer 

-JfUier  reticular /oyer. 

-  CanylioTi,  cell  layer. 
Mrfe  fibre  layer 


Fig.  III. — Nervous  and  Epithelial  Ele- 
ments OF  THE  Retina.     {^After  Stoehr.) 


304  DISEASES    OF   THE    RETINA    AND    OPTIC    NERVE, 

both  visual  fields  lying  to  the  left  of  the  fixation  point  is  obliterated.  That  is  to  say, 
everything  lying  to  the  right  of  the  fixation  point  is  perceived  by  the  left  brain,  every- 
thing to  the  left  by  the  right  brain.  It  is  evident  that  this  can  be  possible  only  when 
the  left  brain  is  connected  with  the  temporal  half  of  the  left  and  with  the  nasal  half  of 
the  right  retina,  and,  vice  versa,  when  the  right  brain  is  connected  with  the  right  halves 
of  the  two  retinas  (^Fig.  112).  It  is  a  consequence  of  this  that  each  optic  nerve  must 
send  part  of  its  fibers  into  the  right  brain,  the  remaining  part  into  the  left  brain, — there 
must  be  a  partial  decussation  of  the  optic-nerve  tracts.  The  location  of  this  decussation 
becomes  a  question  by  itself.  It  is  easy  to  assume  that  the  chiasm  is  the  location  of  this 
partial  decussation,  and  the  most  recent  investigations  of  the  course  of  the  fibers  in  the 
chiasm,  carried  on  by  various  methods,  have  completely  confirmed  this  view,i  although 
this  has  not  put  an  end  to  the  opposition  to  this  theory. 

The  nerve-fibers  proceeding  from  the  eye  continue  from  the  chiasm  along  the  optic 
tract,  to  terminate,  as  has  been  already  mentioned,  in  the  external  geniculate  body  (^4'"- 
113).  A  small  number,  however,  proceed  to  the  anterior  corpora  quadrigemina ;  these 
are  the  fibers  that  control  the  reflex  pupillary  activity,  which  is  thus  completely  outside 


J'txaAorvPoint. 


Xefleye.   ^^^^^^^^^^^''^   Jii^Meye. 


Fig.  112. — The  Binocular  Fielu  of  Vision.     (After  Foerster.) 

The  tracts  from  the  ^ight  brain  are  in  ^ed,  those  from  the  Zeft  brain  are  in  bZ,ue.     The  corresponding 

retinal  halves  and  their  fields  of  vision  are  correspondingly  colored. 

of  man's  will,  and  is  not,  therefore,  like  the  other  eye-movements,  started  by  an  impulse 
from  the  cerebral  cortex.  Consequently  the  pupil  remains  active,  even  if  a  person  is 
blinded  (psychical  blindness)  by  disease  of  the  cortex  of  both  occipital  lobes.  In  such  a 
case  light  stimulation  is  carried  from  the  retina  through  these  fibers  to  the  anterior  cor- 
pora quadrigemina,  from  there  transferred  to  the  anterior  nuclei  of  the  oculomotorius, 
and,  finally,  to  the  iris  muscle,  by  means  of  the  oculomotorius  nerve. 

The  retina  has  its  own  vascular  system.  It  is  supplied  with  blood  from  the  arteria 
centralis  retinae,  a  small  branch  of  the  arteria  ophthalmica  entering  the  optic  nerve  from 
below  about  /j  vim.  behind  the  eyeball.  Beginning  at  the  disc  the  central  artery 
branches  out  over  the  retina  {^Fig.  j/).  After  the  blood  has  passed  through  a  network 
of  the  very  finest  capillaries  it  returns  through  the  retinal  veins  into  the  vena  centralis 
retinae,  which  runs  beside  the  artery  in  the  optic  nerve.  With  the  ophthalmoscope  the 
retinal  vessels  can  be  seen  through  the  eye's  refractive  media,  and  on  account  of  the 
refraction  of  these  media  they  are  actually  magnified.  The  magnification  is  not  enough, 
however,  to  make  visible  the  blood-current  within  the  vessels,  although  this  is  the  case  in 

^  Vesal  thought  he  had  proved  this  partial  decussation  by  demonstrating  a  bundle  of 
fibers  that  had  no  decussation  in  their  course. 


INTRODUCTION. 


305 


the  vessels  of  the  frog's  vitreous.  The  pulse  beat  can  be  easily  perceived  in  man.  The 
venous  pulse  is  common  and  is  to  be  considered  a  physiological  phenomenon.  It  is  seen 
at  the  centermost  end  of  the  retinal  veins,  where  they  bend  at  right  angles  from  the  sur- 
face of  the  nerve  sheath,  to  disappear  within  the  optic  nerve  ;  this  pulse  appears  as  a  regu- 
lar paling  and  reddening  of  this  central  portion  of  the  vein.  The  observer  has  the  impres- 
sion that  the  blood  stream  is  at  each  stroke  dragged  back  toward  the  periphery.  This 
paling  of  the  veins  is  not  synchronous  with  the  radial  pulse  or  the  cardiac  systole,  but  pre- 


eicternuj. 


Musculus  reclus 


Fig.  113. — ScHHMB  of  the  Optic  Tracts.     {After  v.  Monakoiv.) 


cedes  them.  The  cause  of  this  venous  pulse  is  not  yet  fully  explained.  A  visible  arte- 
rial pulse  can  be  obtained  by  continuous  but  gentle  pressure  upon  the  eyeball.  This  is 
not  by  any  means,  as  is  the  venous  pulse,  confined  to  the  center  of  the  papilla,  but  may 
be  followed  as  a  regular  swelling  of  the  arteries  far  out  upon  the  retina ;  this  swelling 
makes  on  the  observer  the  impression  as  of  an  impulse  in  the  direction  of  the  vessels. 
The  phenomenon  is  explained  by  the  fact  that  under  increased  internal  tension  the  blood 
pressure  in  the  arteries  is  not  enough  to  effect  a  continual  flow  of  blood,  but  that  rather 
the  stream  goes  in  spurts  only  at  the  moment  of  the  cardiac  systole.      An  arterial  pulse  is 


306  DISEASES    OF   THE    RETINA    AND    OPTIC    NERVE. 

therefore  always  pathological  and  signifies  a  lack  of  equilibrium  between  arterial  blood 
pressure  and  internal  tension  in  the  eye. 

It  is  due  to  this  visibility  of  the  retinal  vessels  that  we  can  recognize  with  the  ophthal- 
moscope certain  diseases  of  the  general  system,  such  diseases  in  which  the  vessel  walls, 
or  the  amount,  character,  and  distribution  of  the  blood  have  undergone  changes.  It 
must,  therefore,  be  an  inviolable  rule  to  examine  kidneys,  blood-vessels,  and  heart,  as  well 
as  other  structures  of  the  body,  whenever  this  pathological  sign  is  revealed  by  the  ophthal- 
moscope. It  may  happen  that  the  physician  thus  recognizes  a  mortal  disease  in  a  patient 
who  has  sought  advice  on  account  of  some  apparently  transient  disturbance  of  vision. 

It  must  be  a  rule,  also,  carefully  to  examine  the  nervous  system  whenever  the  ophthal- 
moscope reveals  anything  pathological  in  the  optic  disc,  since  diseases  of  the  brain  and 
spinal  cord  very  often  affect  the  optic  nerve  sympathetically,  or,  indeed,  make  their  first 
visible  impression  there.  * 


A.  DISEASES  OF  THE  RETINA. 

I.  HYPEREMIA. 

This  is  detected  at  the  disc  by  an  increase  in  size  of  the  retinal 
vessels  and  by  a  more  h'vely  diffused  redness,  the  capillaries  of  the 
retina  itself  being  too  thin  and  their  network  too  expanded  to  in- 
fluence essentially  the  color  of  the  fundus.  The  enlargement  of  the 
vessels  consists  in  an  increase  in  thickness,  detectable  by  their  darker 
color  and  broader  reflex,  and  in  an  increase  in  length,  detectable  by 
their  greater  varicosity.  There  is  a  hyperemia  from  stasis  and  a 
hyperemia  from  irritation.  Stasis  hyperemia  depends  upon  some 
hindrance  to  the  flow  of  blood  from  the  retinal  veins ;  they  are, 
therefore,  broadened  and  varicose.  If  the  supply  of  arterial  blood 
is  at  the  same  time  restricted,  the  arteries  appear  thinner  and  more 
stretched  out  than  normal,  and  the  contrast  between  the  thickness 
of  the  veins  and  the  thinness  of  the  arteries  becomes  then  particu- 
larly noticeable.  The  diagnosis  of  retinal  hyperemia  is  often  very 
difficult,  because  the  color  of  the  disc  and  the  appearance  of  the 
retinal  vessels  have  quite  wide  limits  within  the  normal,  just  as  the 
young  have,  on  the  average,  redder  cheeks  and  papillae  than  have 
the  old.  In  case  only  one  eye  is  affected,  it  is  advisable  to  com- 
pare one  eye  with  the  other,  paying  especial  attention  to  the  en- 
trance of  the  vessels  into  the  optic  nerve.  The  disc  is  usually  very 
bright  in  the  healthy  eye,  and  any  hyperemia  present  is  therefore 
most  easily  detected  at  that  location. 

Irritatioti  hyperemia  is  usually  an  accompanying  sign  of  inflam- 
mation of  the  cornea,  iris,  or  even  of  the  conjunctiva;  it  may  be  a 


RETINAL    HEMORRHAGE.  3O7 

sign  of  disease  of  the  retina  itself  In  other  and  not  uncommon 
cases,  it  is  an  independent  disease  due  to  abuse  of  the  eyes.  Per- 
sons suffering  from  refractive  errors,  weakness  of  the  internal  recti, 
an  old  conjunctival  catarrh,  are  especially  prone  to  retinal  h}'per- 
emia.  The  symptoms  produced  by  it  consist  in  sensitiveness  to 
bright  light,  exhaustion  on  continued  nearwork,  pain  and  a  feeling 
of  pressure  within  the  eye,  and  nervous  asthenopia. 

Treatment  demands  the  correction  of  any  refractive  errors,  con- 
junctival troubles,  etc.  Protective  glasses  and  rest  to  the  eyes  must 
be  advised.  Congestion  hyperemia  is  almost  always  of  sympto- 
matic significance. 

2.  RETINAL  HEMORRHAGE. 

This  is,  as  a  rule,  only  a  symptom,  appearing  in  almost  all  dis- 
eases of  the  retina.  In  some  cases  it  has  more  of  an  independent 
nature.  Since  the  tension  of  the  eye  presents  a  natural  obstacle  to 
the  rupture  of  an  artery,  and  since  the  ophthalmoscope  shows 
nothing  that  is  significant  of  a  rupture  of  a  vessel,  we  may  assume 
that  retinal  hemorrhages  usually  result  "per  diapedesis,"  and  that 
the  cause  is  to  be  found  in  a  pathological  relaxation  of  the  vessel- 
wall  through  which  the  blood-corpuscles  escape.  Apart  from  in- 
flammations already  mentioned  and  from  injuries,  diapedesis  may 
result  from  arteriosclerosis,  jaundice,  pernicious  anemia,  diabetes, 
scorbutus,  purpura  hemorrhagica — in  fact,  from  all  conditions  that 
encourage  hemorrhage  in  other  organs.  A  further  group  of  retinal 
hemorrhages  is  to  be  ascribed  to  occlusion  (embolus,  thrombosis) 
by  which  the  blood-current  is  disturbed  and  the  vessel-wall  insuffi- 
ciently nourished.  The  form  of  the  blood-clot  differs  according  to 
the  retinal  layer  in  which  the  hemorrhage  occurs.  In  the  inner- 
most layer  the  clot  is  spread  out  in  the  direction  of  the  nerve-fibers, 
and  is  therefore  marked  by  meridional  striations.  In  the  middle  and 
outer  layers  the  blood  follows  the  supporting  layers  of  Mueller's 
fibers  perpendicular  to  the  retinal  surface,  and  appears  to  the  ob- 
server, therefore,  as  a  round  or  irregularly  bordered  blotch.  The 
age  of  the  clot  may  be  estimated  from  its  color,  a  fresh  hemorrhage 
appearing  bluish-red  on  the  bright  red  background  of  the  fundus, 
older  clots  being  rather  brownish-red. 

The  number  and  size  of  the  hemorrhages  differ  decidedly  in  dif- 
ferent cases.  If  they  are  seen  in  an  otherwise  normal  fundus  a 
"  retinal  hemorrhage  "  may  be   diagnosticated.     If,  on  the    other 


308  DISEASES    OF    THE    RETINA    AND    OPTIC    NERVE. 

hand,  the  retina  and  disc  are  hazy,  or  if  other  white  blotches  are 
to  be  seen,  it  is  called  "  retinitis  hemorrhagica."  In  either  case 
there  is,  strictly  speaking,  only  one  pathological  lesion,  the  question 
still  remaining  as  to  the  cause,  from  which  alone  the  real  disease 
and  the  future  of  the  patient  can  be  clearly  determined.  In  the 
majority  of  cases  arteriosclerosis  or  some  heart  disease  can  be  dem- 
onstrated, and  this  may  without  further  evidence  be  set  down  as 
the  cause  of  the  retinal  hemorrhage,  particularly  if  it  happen  to  be 
on  one  side  only. 

The  prognosis  is  unfavorable,  since  a  cerebral  hemorrhage  is  apt 
to  follow  a  retinal  hemorrhage  sooner  or  later.  The  visual  disturb- 
ance depends  upon  the  location  and  size  of  the  clot;  it  may  be  of 
little  consequence  if  seated  in  the  periphery.  As  the  blood  is 
absorbed  the  visual  disturbance  may  disappear  altogether.  The 
occurrence  of  multiple  hemorrhages  may  have  a  bad  local  prog- 
nosis,since  they  may  be  advance  symptoms  of  a  hemorrhagic  glau- 
coma, which  nearly  without  exception  ends  in  blindness. 

Treatment  must  be  directed  to  the  maintenance  of  the  patient's 
health.  Locally,  a  pressure  bandage  should  be  used  to  encourage 
absorption.     Of  course  the  eye  must  be  kept  at  rest. 

3.  INFLAMMATIONS. 

The  retina  is  little  inclined  to  idiopathic  disease.  Its  inflamma- 
tions are  almost  always  due  to  some  disease  of  the  general  system, 
the  nature  of  which  produces  a  corresponding  change  in  the  retina, 
so  that  it  is  at  times  possible  to  infer  from  the  ophthalmoscopic 
picture  whether  the  retinitis  is  albuminuric,  leukemic,  or  syphilitic. 
In  other  cases,  to  be  sure,  the  ophthalmoscope  shows  nothing  diag- 
nostic, while  it  does  infrequently  happen  that  the  fundus  changes 
of  one  disease  are  due  to  another  of  entirely  different  origin.  The 
condition  discovered  by  the  ophthalmoscope  is,  therefore,  but  an 
indicator  ;  the  actual  diagnosis  must  be  sustained  by  systematic 
evidence  of  albuminuria,  diabetes,  or  of  syphilis. 

{a)  Retinitis  Albuminurica. — This  disease  is  almost  always 
bilateral.  Light-sense,  color-sense,  and  field  of  vision  remain 
unchanged.  Visual  acuity  is  in  some  cases  unaffected,  so  that  the 
kidney  disease  is  first  recognized,  the  retinal  inflammation  later.  In 
other  cases  vision  is  slightly  disturbed,  fine  print  seeming  to  be 
read  through  a  veil ;  but  in  others  again,  it  is  difficult  even  to  count 
fingers.     Complete  blindness  is  not  produced,  for  though  it  occa- 


RETINITIS    ALBUMINURICA. 


309 


sionally  occurs,  it  is  not  due  to  the  retinal  changes  but  to  uremia 
(uremic  amaurosis,  q.  v.).  In  a  disease  which  extends  over  months 
or  years,  the  ophthalmoscopic  changes  differ  obviously  in  its  various 
stages.  All  stages,  however,  have  this  in  common,  that  t/ie  clianges 
in  tlie  fundus  arc  confined  to  the  posterior  pole  arid  a  region  beyond  it 
of  J  to  ^  papilla  breadths.  At  first  there  is  hyperemia  and  haziness 
of  the  disc,  occasionally  hemorrhages  in  the  nerve-fiber  sheath, 
which  are  therefore  striated  and  arranged  like  spokes  radiating 
toward  the  papilla.  As  the  disease  advances  there  are  seen  white 
spots  arranged  in  circles  about  the  papilla,  leaving  the  macula  lutea 


Fig.  114. — Papillo-Retinitis  in  Bright's  Disease.     {After  Liebreich) 

tree,  however ;  but  the  latter  is  marked  by  very  fine  white  dots, 
giving  the  darker  macula  the  appearance  of  being  specked  with 
white  paint  {Fig.  nf)-  These  specks  form  a  star-figure,  at  the  cen- 
ter of  which  lies  the  fovea  centralis.  They  are  areas  of  Mueller's 
supporting  fibers  infiltrated  with  fat.  The  large  white  spots  are 
areas  of  the  two  granular  layers  that  have  undergone  fatty  degen- 
eration. During  the  last  stage  of  the  disease  the  hemorrhages  and 
fatty  foci  disappear  as  the  signs  of  atrophy  become  evident — pale- 
ness of  the  disc  and  contraction  of  the  vessels.  The  last  stage  is 
seldom  reached  before  the  patient  dies. 


3IO  DISEASES  OF  THE   RETIKA  AND   OPTIC   NERVE. 

Aibuminuric  retinitis  may  at  tiroes  be  evidenced,  not  by  the  white 
^)Ots  and  fev  hemorrhages,  but  by  congestion  and  redness  of  the 
disc,  a  true  papillitis  (/^.  114) ;  or  by  numerous  hemorrhages  scat- 
tered over  tlie  wlnrfe  fundus,  a  retinitis  hemorrhagica.  It  must  be 
stated,  too,  that  hemorrhages  and  hyperemia  may  both  be  present 
with  the  fiitly  fod. 

The  intimate  conncctiofi  between  kidne\'  and  retina  is  not  quite 
dear.  Many  assume  that  the  retinitis  is 'caused  by  the  nephritis; 
oCiiers — Michel,  for  example— declare  that  both  diseases  have  the 
same  pathological  basis,  a  hyaline  degeneration  o€  the  vessels  of  the 
choroid  and  retina,  and  of  those  of  the  kidney. 

The  progno^  is  un&vorable,  less  for  visual  acuit>'  than  for  life. 
Retinitis  albuminurica  is  seen  oftener  with  the  contracted  kidney 
(nephritis  interstitialis  I.  a  chronic  disease  leading  to  death  within  a 
few  years.  Even  in  these  cases  a  temporary-  improvement  in  the 
retinitis  is  not  impossible.  If  retinitis  albuminurica  appears  during 
acute  nephritis,  the  retina  may  become  normal  again  if  the  kidney 
trouble  is  cured. 

Treatment  most  coincide  with  that  for  the  original  disease ;  sys- 
tematic diaphoresis,  with  plain  milk  diet,  will  perhaps  give  the  best 
results. 

(i)  Retinim  Diabetica. — ^The  aost  geaeral  s^  of 
Itj"  gjkasana  is  hcaKHxhig^  RtHins.     The  seooad  aad  verjr  ( 
Ihi  liimwi.  vhkk  pnfaabif  ii  dae  to  keannlMee  widaa  it.     Lcb  cobhkm  sipB  ave 

iiliili    |iiili  Alt  WTTI r^ '  ''^'    —  -^—  -^  -      •'  •-'      *    III    n '1         The 

iiyhlhilMiirnirr  nlinr.  T^rrrfTrr-.  "  -r  -"-  V  rr-*-^^  T*-r  if  npinrir  HiiwMicig  las 
larlr  lirrlTil  ihiT  riinr  is  a  farm  of  iiliailii  dhhrtir^  act  to  be  coafcsed  widi  oOcr 
■ctiaal  iaCiaBHiiaas,  opecia^  nedMbs  alhaaiaarieB.     lie  cafls  Ais  ioito  netimHi$  ctm- 

(i)  'Sam^andkmmcat.  of  Ac  opdc-aerwe  skeaih  ; 

(2)  "'—iiiiBi  Mil    iij  fBiill    iTiili   1I11I1  mill  ■iialilalii  lailili  i— iilialL  m\v^\ 


aad  Ante  heaHndbages  between  dMse  white 

hf  ao  toeaiB  releases  ar  firiai  ihi  am  iiij 

is  faiblenl,  akhaadk  act  the  saaw  in  both  eyes. 

thai  ofdbaMBnric  idinitis,  iMmm^  Aere  aie,espe- 

fcnat  of  fcljiwaili      The  treatment  is  not 

fate,  bodily  hygiene,  aascaiar  rxodse,  a  cxmne 

the  ariae  and  iatAit,  if  it  cannot  one,  the 


[f)  Brtiwitis  LinWiiri — la  ^wcwKinncrd  cases  of  Irnliaiij  dbe  changed  rhaiaftfr 
of  Ae  Hand  ii  to  be  delected  by  Ae  noticxnUy  pde  eaior  of  dK  Inndns.     Imead  of 
it  looks  jdDow  ;  dK  Rtiaai  arteries  are  pale  ydlov,  Ae  vens 


EMBOLUS  OF  THE  ARTERIA  CENTRALIS  RETIN-E,       3II 

pal«  red,  and  are  accoinpaaied  by  wiatiak  bnes ;  the  rrlMi  itedf  is  moderately  tiomif. 
In  aboot  ooe-third  of  t^  eaats  a  nlwilii  is  pnt^mvA,  ahn^s  bBateral.  If  tUs  s 
m  tbe  typical  fomL,  it  is  recognized  by  tbe  dnaalax  cSots  and  wUte, 
bordered  spots,  whicb  lie  at  the  periphery  of  the  retina  rather  thaa  at  1 
of  the  disc.  This  is,  kowcrer,  not  always  the  case.  PrfiMTir  leafcaMJca  may  asome  tbe 
character  of  tbe  heiBorrlu^ic  type.  The  disdnction  mmSt  ke  laade  by  a  microscopical 
examination  of  the  blood,  in  which  the  iaocased  fnwtiiMi  of  white  aod  decreased  pp&- 
portioD  of  red  blood -corposcles  is  di  iniiJiiliiXl 

(li)  Retinitis  syphilitica,  in  i.iMtiaili  liiiction  to  die  three  locaEzed  diseases,  is  a 
di&ise  retinal  ifiSiMBBation.  It  mucf  be  taAex  — flatfral  or  lalateraL  Itisevidcaoedby 
a  doadiBess  of  gjieater  or  leM  deasitr,  aott  appatait  at  the  entrance  of  the  optic  aovc, 
the  ed^e  of  the  disc  b«ng  quite  ut»f«<i,  tbe  doodiness  gradoally  disappearing  only  at 
quite  a  distance  into  the  retina.  It  tsUumh  the  coarse  of  the  large  blood-Tcssels  in  the 
chancier  of  wUle  striarinac  tiLauBi«e  or  ciitilrttTy  ouwriiag  (bea  a  places.  These 
sbiatJoBS  give  Ae  <ipli&Blansoapic  fadiR  of  a  naad-edi  laffltntfia  ia  aad  akxe^  the 
Tessel  walL  The  real  |nii|Atiy  «f  &e  fandas  vemias  free.  Hoaankaees  md.  ag^ 
of  great  hj^ieirMii  are  aiailly  laiiai^.  If  Ac  ritreoas  is  at  tbe  saag  tiaie  opaqae  d^ae 
is  achororetinidsqrphilitira  (Foeister) ;  ior  tbe  prognoss  aitd  treataient  of  wrhidi  the  ste- 
dent  is  referred  to/,  ^q^ 

4-  OCCLUSION  OF  THE  RETINAL  VESSELS. 
(a)  Embolus  of  the  Arteria  Centralis  Retinae. — The  retinal 
vessels  form  an  independent  temtor\-  in  the  circulation,  there  being 
a  connection  with  the  posterior  dliary  arteries  through  capillary- 
anastomoses  only  at  the  region  of  the  optic  ner\-e  (/v^.  pj,  /.  36^). 
For  that  reason  the  nutrition  of  the  retina  ceases  at  any  stoppage 
of  the  arterior  centralis,  since  there  is  no  anatomical  assumption  for 
the  development  of  collateral  circulation.  The  blood  would  flow 
back  from  the  veins  into  the  empty  retinal  arteries  and  cause  a  hem- 
orrhagic infarct  if  it  were  not  that  the  tension  within  the  eye  is 
higher  than  the  blood  pressure  in  the  veins,  and  that,  therefore,  the 
return  wave  is  prevented.  The  ophthalmoscope  shows  in  a  recent 
case  of  embolus  of  the  central  artery  an  extreme  degree  of  ischemia, 
with  the  papilla  pale,  the  arteries  reduced  to  threads,  the  veins 
thinned  (but  not  so  conspicuously  as  the  arteries)  and  pulseless. 
The  retinal  starvation  produces,  within  a  few  hours  even,  certain 
visible  ophthalmoscopic  changes,  such  as  striated  cloudiness  of  the 
disc  and  a  milk-like  cloudiness  of  the  macula  lutea  in  which  the 
fovea  centralis  is  outlined  as  a  blood-red  point,  the  retina  being 
here  so  thin  that  the  red  of  the  choroid  is  transmitted ;  this  dark 
jxjint  must  be  considered  as  an  effect  of  contrast,  not  as  a  hemor- 
rhage. There  are,  however,  small  punctate  or  striate  hemorrhages 
to  be  found,  generally  between  optic  nerve  and  macula  lutea.  Dur- 
ing the  next  few   weeks  the  circulation  is   to    some   incomplete 


312  DISEASES    OF   THE    RETINA    AND    OPTIC    NERVE, 

extent  restored,  the  retinal  cloudiness  and  the  redness  of  the  fovea 
centralis  disappear,  but  the  evident  signs  of  atrophy  develop  ;  the 
disc  is  pale  and  the  vessels  persist  only  as  thin  white  lines.  It  is 
easy  to  imagine  the  effect  of  an  embolus  on  the  visual  acuity!  At 
the  moment  of  the  accident  the  circulation  stops,  vision  ceases,  the 
eye  is  blind.  This  may  happen  so  instantaneously  that  the  patient 
in  full  health  stoops  to  pick  up  an  object,  only  to  find  himself  blind 
when  raising  up  again.  There  may  be  a  temporary  improvement 
during  the  succeeding  weeks,  but  the  result  is  incurable  blindness, 
amaurosis. 

The  diagnosis  of  the  strange  disease  depends  upon  the  sudden 
blindness  in  one  eye,  the  characteristic  ophthalmoscopic  image,  and 
the  discovery  of  some  source  of  the  embolus,  either  an  endocarditis, 
an  aneurism,  some  valvular  disease,  or  a  new  growth  in  some  part 
of  the  body;  it  is  not  improbable  that  some  fragment  maybe  loos- 
ened from  new  growths  and  become  carried  along  the  blood  cur- 
rent. In  an  examination  of  reported  cases  Kern  has  been  able 
to  demonstrate  one  of  these  causes  in  only  one-third  of  them. 
We  must  assume,  therefore,  that  in  the  majority  (two-thirds)  of 
cases  the  circulation  is  interrupted  by  some  local  disease  of  the  cen- 
tral artery  rather  than  by  an  embolus.  We  may  assume  that  a 
thrombus  suddenly  results  from  an  endocarditis  (due  to  syphilis, 
arteriosclerosis,  or  nephritis),  and  have  the  same  mechanical  effect 
as  an  embolus.  We  must  recall  v.  Graefe's  theory,  too,  that  a 
severe  inflammation  of  the  optic  nerve  with  the  associated  com- 
pression of  the  artery  with  it,  may  simulate  embolism. 

(d)  Embolism  of  individual  branches  of  the  retinal  artery  has  been  often 
observed  and  described.  At  the  spot  where  the  embolus  lies  the  artery  appears  swollen 
and  spindle-shaped  ;  beyond  it,  the  artery  is  thread-like,  thin,  and  empty.  The  condi- 
tions for  the  production  of  a  hemorrhagic  infarct  are,  of  course,  much  more  favorable  than 
in  stoppage  of  the  main  artery,  and  consequently  there  are  apt  to  be  numerous  hemor- 
rhages within  the  territory  of  the  occluded  branch ;  there  is  also  cloudiness  of  the  retina 
and  the  final  atrophy.  The  condition  corresponds  to  that  of  "  retinitis  hemorrhagica," 
and  Leber  may  be  correct  in  tracing  retinitis  hemorrhagica  to  multiple  embolism  of  the 
finer  vessels.  The  visual  disturbance — apart  from  the  immediate  but  transient  obscura- 
tion of  the  central  vision — is  limited  to  a  portion  of  the  field.  If  the  upper  or  lower 
principal  branch  is  occluded,  the  perimeter  shows  a  lower  or  upper  scotoma.  If  a  branch 
of  the  second  degree  is  occluded,  a  correspondingly  situated  scotoma  in  the  form  of  a 
sector  will  be  demonstrated.  If  the  case  is  very  recent  and  treated  at  once,  the  attempt 
may  be  made  to  drive  the  embolus  into  a  smaller  artery  by  massage  to  the  eye  or  by 
reduction  of  the  internal  tension  (sclerotomy). 

(f)  Septic  Embolism. — If  the  occluding  plug  consists  of  or  contains  bacteria  it  acts 
not  only  mechanically  but  septically,  that  is,  it  produces  suppurative  infiltration  of  the 


PIGMENT    DEGENERATION.  3I3 

innermost  retinal  layer,  then  of  the  entire  retina,  and  finally  of  the  eye,  the  condition 
being  that  of  panophthalmitis  (/.  2g6). 

((/)  Thrombosis  of  the  Vena  Centralis. — Michel  has  observed  and  reported  a 
few  cases.  The  disease  is  betrayed  by  the  signs  of  pronounced  stasis  in  the  retinal  veins, 
which  appear  purplish,  dilated,  and  tortuous;  "the  entrance  of  the  optic  nerve  and  its 
immediate  neighborhood  seem  to  be  daubed  in  blood,"  although  a  delicate  striation  is 
still  visible  upon  it ;  the  rest  of  the  retina  is  strewn  with  large  and  small  hemorrhagic 
blotches  or  striations.  It  does  not,  like  embolism,  lead  to  direct  blindness,  but  the 
visual  disturbance  is  severe  and  passes  gradually  into  a  blindness  susceptible  of  a  certain 
improvement  if  the  circulation  is  restored  to  any  extent.  Michel  considers  the  cause  to 
be  an  arteriosclerosis  with  a  poorly  nourished  condition  of  the  patient,  classing  the  disease, 
therefore,  among  the  marantic  thromboses. 


5.  PIGMENT  DEGENERATION  {Retinitis  pigmentosa). 
This  disease  has  three  signs  that  give  it  an  unusually  plain  indi- 
viduality.    These  are  : — 

(i)  Hemeralopia  (night-blindness)  ; 

(2)  Concentric  contraction  of  the  field  of  vision ; 

(3)  A  characteristic  ophthalmoscopic  image. 

Hemeralopia  {q.  v.)  is,  as  a  rule,  the  symptom  that  first  attracts 
the  patient  and  his  associates,  and  finally  impels  him  to  seek  the 
physician.  At  night  he  is  blind  and  helpless  in  a  light  that 
would  be  quite  sufficient  to  guide  the  healthy  person  about.  Dur- 
ing the  day  these  "  night  shadows,"  that  is,  the  reduced  sensitive- 
ness of  the  retina  to  weak  stimulation,  can  easily  be  detected  (see 
Perception  of  Light,  /.  jj). 

One  patient  told  me  that  while  I  stood  with  my  back  to  the  window  he  could  see  only 
the  edges  of  my  ears,  but  that  as  soon  as  my  face  was  well  lit  up,  he  could  detect  every- 
thing distinctly. 

The  concentric  contraction  of  the  visual  field  becomes  so  great 
during  the  course  of  the  disease  that  the  patient  can  scarcely  find 
his  way  about  (/.  62),  even  in  broad  daylight,  and  in  spite  of  a 
very  good  visual  acuity ;  he  may  read  fine  print  and  yet  be  unable 
to  cross  the  street  alone.  Central  vision  is,  however,  in  the  major- 
ity of  cases  noticeably  reduced,  to  — ,  —7-,  or  even  more ;  it  may 
even  happen  that  this  reduction  of  central  vision  is  the  cause  of 
visiting  the  physician.  The  pronounced  reduction  of  visual  acuity 
is  often  coupled  with  nystagmus. 

The  fundus  appears  as  follows :  the  disc  is  yellowish  or  reddish- 
gray,  its  edges  somewhat  obscured  ;  the  vessels  are  narrow,  accom- 
panied by  fine  white  bands,  and  cannot  be  traced  so  far  toward  the 


314  DISEASES    OF   THE    RETINA    AND   OPTIC    NERVE, 

periphery  as  under  normal  circumstances.  Toward  the  edges  of 
the  retina  there  are  numerous  black  pigment  deposits,  shaped  like 
"  bone-corpuscles  "  {Fig.  iij),  the  outrunners  of  this  jagged  con- 
figuration being  attached  to  form  a  black  network.  These  spots  of 
pigment  lie  in  the  course  of  the  retinal  vessels,  the  place  of  sub- 
division in  them  being  particularly  selected  for  the  deposits.  As 
the  disease  progresses  the  network  of  pigment  approaches  closer 
and  closer  to  the  posterior  pole  of  the  eyeball. 

Anatomically  it  has  been  shown  that  the  vessel  walls  are  thick- 
ened and  the  lumen  of  the  vessels  narrowed ;   that  the  connective 


Fig.  115. — Retinitis  Pigmentosa.     {After  Litbreick^ 
The  papilla  is  atrophic,  the  vessels  constricted. 

tissue  of  the  retina  is  hypertrophied  and  its  nervous  elements,  par- 
ticularly the  layer  of  rods  and  cones,  atrophied ;  finally,  that  the 
retinal  pigment  cells  have  spread  out  even  as  far  as  the  innermost 
layer. 

The  beginnings  of  the  disease  can  usually  be  traced  to  heredity; 
the  end — complete  blindness  in  both  eyes — may  not  be  reached 
for  fifty  years.  Cases  have  been  reported  in  which  the  trouble  was 
detected  no  earlier  than  the  fifteenth  or  twentieth  year,  but  of 
course  there  will  always  be  the  doubt  whether  it  had  not  been  pre- 
viously overlooked. 

The  causes  are  unknown.     It  is  congenital ;  and  the  fact  that  this 


DETACHMENT    OF    THE    RETINA. 


315 


pigment  degeneration  occurs  commonly  in  members  of  the  same 
family,  and  associated  with  deafness,  idiotism  or  some  abnormality, 
supports  the  conviction  that  the  patient's  parents  bear  the  guilt. 
Blood-relationship  is  probably  of  significance.  Syphilis  may  play 
its  part,  and  especially  congenital  syphilis,  since  choroiditis  from  it 
{p.  2^/f)  may  present  a  condition  so  similar  as  to  lead  to  confusion 
with  pigment  degeneration.  A  thorough  inquiry  into  the  patient's 
history  may  aid  in  distinguishing  the  two  conditions. 

Treatment  is  futile.  The  patient  must  be  kept  in  good  health 
and  spirits,  and  made  to  look  upon  the  matter  as  hopefully  as 
possible. 


6.  DETACHMENT  OF  THE  RETINA. 

This  implies  a  detachment  of  the  retina  from  its  natural  bed,  the 
choroid.  Every  retinal  detachment  begins  in  a  partial  manner,  and 
if  it  increases,  it  gradually  extends  until  it 
finally  becomes  complete  {Fig.  116).  The 
retina  is  then  attached  only  behind,  to  the 
optic  nerve,  and  in  front  to  the  ciliary  body, 
forming  a  funnel  something  like  a  convolvu- 
lus blossom. 

Before  the  detachment  occurs,  there  are 
usually  such  warning  symptoms  as  flicker- 
ings,  the  appearance  of  sparks,  and  attacks 
of  momentary  blindness.  The  detachment 
then  takes  place  suddenly,  the  effect  on  the 
patient  being  that  of  a  dark  cloud  before  his 

eyes  obscuring  the  field  of  vision.  The  function  of  the  detached 
portion  of  the  retina  is  only  impaired,  but  not  at  first  destroyed,  for 
it  is  still  nourished  by  its  own  vessels.  This  detached  portion  falls  in 
front  of  the  posterior  focal  point  of  the  (emmetropic)  eye,  and  there- 
fore receives  only  an  indistinct  dioptric  image,  like  that  of  a  hyper- 
opic  eye  at  rest.  The  refractive  condition  is  changed,  so  much  so 
that  in  pronounced  myopia  the  patient  may  imagine  his  myopia 
has  been  cured  !  The  detached  portion  is  not,  however,  parallel  to 
the  posterior  focal  surface,  but  is  thrown  into  folds ;  external  ob- 
jects appear,  therefore,  bent  and  distorted — metamorphopsia.  This 
curtain  is  not  quiet,  but  swings  hither  and  thither  at  every  move- 
ment of  the  eye,  because  there  is  fluid  before  and  behind  it ;  objects, 
therefore,  appear  to  float  through  each  other.     These  phenomena 


Fig.  116.  —  Pedunculated 
Retinal  Detachment. 
{After  Pagenstecher  and 
Genth.) 


3l6  DISEASES    OF   THE    RETINA    AND    OPTIC    NERVE, 

disappear  after  the  detachment  has  lasted  some  time,  since  the 
detached  portion  gradually  fails  in  function.  The  perimeter  shows 
a  scotoma  corresponding  approximately  in  size  to  the  extent  of  the 
detachment. 

The  undetached  portion  also  is  usually  injured,  as  may  be  recog- 
nized by  the  reduction  of  the  central  visual  acuity  and  by  the  tor- 
por retinae:  the  sluggish  response  of  the  retina  to  moderate  impres- 
sions of  light.  These  subjective  phenomena  vary  considerably, 
since  the  detachment  changes  its  position  as  a  rule,  if,  as  usually 
is  the  case,  the  retina  was  first  detached  above,  it  separates  gradu- 
ally downward,  the  upper  retinal  half  becomes  again  attached,  its 
function  returns,  and,  after  the  appearance  of  sparks  and  such  like 
phenomena  of  light,  the  lower  retinal  half  is  partly  and  later  entirely 
incapable  of  functionating. 

Detachment  of  the  retina  is  demonstrable  objectively  if  the  oph- 
thalmoscope shows  in  the  fundus  a  membrane  marked  like  the 
retina  with  blood-vessels.  The  color  of  the  prolapsed  retina  is  from 
white  to  bluish-gray.  Pigment  can  seldom  be  seen,  as  the  pigment 
epithelium  remains,  as  a  rule,  adherent  to  the  choroid.  The  sur- 
face of  the  detached  portion  of  the  retina  is  thrown  into  many  folds 
after  having  such  regular  striae  that  it  looks  like  a  series  of  steps  ; 
it  waves  to  and  fro  as  the  eye  is  moved ;  sometimes  a  rent  with 
inverted  edges  may  be  found.  The  vessels  appear  very  dark, 
nearly  black,  and  have  no  reflex ;  where  they  pass  over  a  fold  they 
seem  to  be  broken  off.  This  picture  may  be  confused  by  vitreous 
opacities  that  are  to  be  discovered  to  some  extent  in  nearly  all  retinal 
detachments.  The  tension  is  probably,  and  in  old  cases  certainly, 
reduced. 

Detachments  of  the  retina  occur  in  various  diseases.  In  injuries, 
both  old  and  new,  for  example — in  the  latter  case  there  being  the 
traction  made  by  cicatricial  tissue  that  has  developed  within  the 
eye.  Chronic  inflammations  of  the  eye  or  of  the  retina  alone  may 
lead  to  a  detachment.  The  most  common  cause  is,  however,  disease 
of  the  choroid  and  indirectly  of  the  vitreous,  resulting  from  pro- 
nounced myopia.  New  growths  (sarcoma,  tubercle)  and  parasites 
(g.  2f.)  must  be  thought  of.  If  none  of  these  causes  can  be  dis- 
covered we  must  call  it  an  idiopathic  detachment,  which  only 
means  that  we  do  not  know  the  cause.  We  may  assume  that  occa- 
sionally a  thread-worm  or  some  other  parasite  has  caused  the  mis- 
chief. 


DETACHMENT    OF    THE    RETINA.  317 

The  mechanism  of  a  detachment  is  not  yet  quite  clear,  in  spite  of  numerous  and  pains- 
taking investigations.  TJie  conditions  after  an  injury  are  the  easiest  to  explain.  If,  in  a 
cataract  extraction  or  any  other  opening  in  the  eyeball,  some  vitreous  escapes,  the  eye's 
tension  falls,  and  the  retina,  being  no  longer  pressed  against  the  choroid,  there  is  noth- 
ing to  prevent  a  hemorrhage  due  to  the  injury  from  taking  place  behind  the  retina  and 
pressing  it  forward.  If  any  disease  of  the  vessel  walls  predisposes  to  hemorrhage,  a  loss 
of  vitreous  may  not  be  necessary,  the  sudden  reduction  in  tension  due  to  escape  of  aque- 
ous sufficing.  It  is,  therefore,  a  good  rule,  where  performing  an  iridectomy  for  glau- 
coma, to  allow  the  aqueous  to  escape  very  gradually.  Even  if  the  capsule  is  not  opened, 
a  sudden  blow  (champagne  corks  striking  the  eye  !)  may  cause  small  hemorrhages  behind 
the  retina  and  a  subsequent  detachment.  Strange  to  say,  the  tension  is  reduced  after 
such  an  accident.  The  opposite  would  be  expected,  since  a  hemorrhage  behind  the 
retina,  even  of  only  a  few  drops,  would  increase  the  contents  of  the  eyeball.  In  the  same 
way  increased  tension  would  be  expected  in  detachments  due  to  other  extravasations 
(serum  or  pus)  behind  the  retina.  Except  in  the  case  of  new  growths,  however,  such  is 
not  the  case.  Leber  has  attempted  to  explain  this  apparent  contradiction  as  follows : 
the  ultimate  cause  of  a  detachment  of  the  retina  is  usually  a  contraction  of  the 
vitreous  ;  this  results  in  a  vitreous  detachment,  leaving  between  contracted  vitreous 
and  retina  a  space  filled  with  serum  {M^.  ijS).  But  the  atrophic  connective-tissue 
fibers  of  the  vitreous  are  in  some  places  adherent  to  the  retina,  and  in  contracting 
they  drag  the  retina  with  them  to  produce  a  retinal  detachment  or  laceration.  The 
fluid  in  front  of  the  retina  can  now  pass  behind  it  through  the  laceration  and  so  increase 
the  detachment. 

This  theory  is,  for  the  present,  antagonized  by  the  "  diffusion  theory."  If  an  eyeball 
is  preserved  in  alcohol,  a  retinal  detachment  always  takes  place.  This  is  explained  by 
the  fact  that  the  alcohol  penetrates  the  retina  and  extracts  water  from  the  vitreous ;  the 
vitreous,  therefore,  contracts,  while  the  fluid  between  retina  and  choroid  increases, 
the  result  being  to  push  the  retina  into  the  space  occupied  by  the  vitreous.  The  basis  of 
the  diff^usion  theory  lies — 

(/)  In  the  fact  that  the  fluid  found  behind  the  prolapsed  retina  is  always  quite  albu- 
minous, although  the  vitreous  has  only  a  trace  of  albumin  (i  :  looo)  ;  and 

(.?)  In  the  fact  that  a  retinal  detachment  can  be  produced  artificially  by  injecting  sodic 
chlorid  solution  into  the  vitreous,  while  the  exposed  choroid  is  simultaneously  dipped  into 
a  solution  of  albumin. 

The  philosophy  of  the  matter  seems  to  be  this  :  some  chemical  change  in  the  vitreous, 
not  yet  understood,  but  probably  demonstrable  by  the  ophthalmoscope  as  "  fluidity  of  the 
vitreous"  {(/.v.),  proves  the  starting-point.  The  diffusing  "vitreous  salts"  cause  a 
very  albuminous  fluid  to  collect  behind  the  retina;  since,  by  diffusion,  more  and  more  of 
the  ingredients  of  the  vitreous  collect  behind  the  retina,  it  is  pushed  more  and  more  in- 
ward till  it  finally  gives  way. 

•  In  support  of  the  diffusion  theory,  and  in  opposition  to  that  of  Leber,  Raehlmann  has 
introduced  a  number  of  clinical  and  pathological  facts.  Clinically,  for  example,  it  is 
known  that:  retinal  detachments  occur  not  only  in  eyes  of  reduced  and  of  normal,  but 
also  in  eyes  of  increased  (glaucomatous)  tension ;  they  may  occur  suddenly,  at  night ; 
they  not  infrequently  progress  downward  (a  solution  of  albumin  being  specifically  heavier 
than  vitreous) ;  and  that  the  prolapsed  retina  attaches  itself  again  and  heals  in  place  if 
the  albuminous  exudate  is  absorbed.  Pathologically,  it  is  known  that  fibrillary  vitreous 
contraction  and  adhesion  between  vitreous  and  retina  have  not  been  demonstrable  in  all 
cases  of  retinal  detachment,  and  that  demonstral)le  atrophy  of  the  vitreous  has  not  always 
been  attended  bv  a  retinal  detachment. 


3l8  DISEASES    OF    THE    RETINA    AND    OPTIC    NERVE. 

The  prognosis  depends  upon  the  cause.  Relatively,  the  best  case 
is  that  due  to  a  parasite  in  the  eye,  since  its  early  extraction  may 
effect  a  cure.  It  is  very  grave  in  pronounced  myopia,  since  one 
eye  after  the  other  is  attacked  in  spite  of  all  precaution,  and  blind- 
ness becomes  unavoidable.  If  the  cause  is  undiscoverable,  the  out- 
look is  bad.  The  prognosis  is  very  grave  in  sarcoma  and  tuber- 
culosis (/».  2g6). 

Treatment,  too,  depends  upon  the  cause.  If  the  cause  is  un- 
known, or  if  there  is  nothing  particularly  to  attack,  we  should  \.xy 
prolonged  rest  in  bed  with  pressure  bandage,  and  salicylate  of 
sodium  (to  4.0  grams  daily),  or  muriate  of  pilocarpin  (to  0.02  gram 
daily),  with  the  hope  of  obtaining  their  resorptive  action  through 
the  diaphoresis  they  produce.  If  no  result  shows  itself,  an  opera- 
tion may  be  thought  of  Sichel  recommended  puncture  through 
both  exterior  membranes  in  order  to  allow  the  subretinal  fluid  to 
escape.  Schceler  injects  a  few  drops  of  tincture  of  iodin  into  the 
vitreous  in  front  of  the  prolapsed  retina.  Sichel's  principle  is  about 
as  easy  as  Schoeler's  is  hard  to  understand.  Both  are  reported  to 
have  given  brilliant  results — and  very  bad  ones  as  well,  for  the  in- 
jection of  iodin  has  caused  death.  It  is  hard  to  estimate  the  value 
of  these  methods,  since  it  not  infrequently  happens  that  the  pro- 
lapsed retina  becomes  again  attached  with  no  treatment  whatever, 
and  occasionally  a  cure  is  thus  obtained. 

7.  GLIOMA  RETIN.E. 

The  connective  tissue  of  the  central  nervous  system  is  called 
neuroglia ;  as  the  retina  is  morphologically  a  part  of  the  brain,  its 
connective  tissue  also  is  neuroglia.  A  tumor  developing  from  the 
cells  of  this  neuroglia  is  called  a  glioma.  It  is  soft  and  rich  in 
blood,  having  a  great  resemblance  histologically  to  a  sarcoma,  for 
it  consists,  as  do  sarcomata,  almost  entirely  of  small  round  cells  with 
a  large  nucleus  and  but  little  protoplasm,  having  a  very  trifling 
amount  of  connective  tissue.  Gliomata  belong  with  sarcomata 
among  the  malignant  growths.  The  glioma  has,  therefore,  been 
called  a  neuroglia-sarcoma. 

A  glioma  usually  begins  as  a  flat  nodule  in  one  of  the  inner 
retinal  layers,  most  frequently  the  inner  granular  layer.  As  this 
nodule  grows  toward  the  surface  it  reaches  the  exterior  of  the  retina 
and  produces  a  detachment — the  more  common  occurrence ;  or  it 
grows  toward  the  vitreous  and  projects  into  it  as  a  lump  or  promi- 


GLIOMA    RETIN.E.  3I9 

nence.  From  now  on  all  the  signs  of  an  eye  tumor  become  evi- 
dent, as  have  been  described  under  Sarcoma  of  the  Choroid  (/.  2gf). 
Glioma  has  much  in  common  with  this  disease :  blindness,  perfora- 
tion of  the  wall  of  the  eye,  involvement  of  neighboring  tissues,  met- 
astasis to  other  parts  of  the  body,  and  the  final  death.  There  are, 
however,  some  differences  depending  less  upon  the  nature  of  the 
tumor  than  upon  the  fact  that  glioma  occurs  nearly  without  excep- 
tion in  children  from  one  to  four  years  old,  sarcoma  attacking  adults 
from  forty  to  sixt\'. 

The^rj/  stage  of  the  disease  is  apt  to  be  quite  overlooked,  since 
small  children  take  no  notice  of  the  early  subjective  symptom — 
visual  disturbance.  When  the  tumor  or  the  detached  retina  has  come 
so  far  for^\'ard  that  the  light  reflected  from  it  is  visible  as  a  bright 
shimmer  in  the  pupil,  the  parents  themselves  notice  it,  and  then 
they  find  that  the  eye  is  already  blind.^ 

The  ophthalmoscope  shows  a  reddish  or  yellowish-white  promi- 
nence surrounded  by  small,  pale  yellow  nodules ;  numerous  well- 
dilated  retinal  blood-vessels  conv^erge  toward  this  tumor.  Beyond 
it  the  retina  may  appear  either  normal  or  prolapsed. 

In  the  second  stage,  increased  tension  with  its  consequences 
approaches  (/.  2g8)  slowly  at  first,  because  of  the  elasticity  of  the 
juvenile  sclera  ;  or  there  may  be  the  signs  of  internal  inflammation, 
opacity  of  the  cornea  and  aqueous,  occasionally  posterior  synechiae, 
dilatation  of  blood-vessels  in  the  conjunctiva  and  lid ;  the  cornea 
may  ulcerate,  and  after  perforation  takes  place  the  eye  may  col- 
lapse. But  this  condition  does  not  last  very  long.  After  a  longer 
or  shorter  interval  the  tumor  grows  more  rapidly  and  escapes 
through  the  perforation  or  makes  a  way  for  itself  through  the  sclera. 
Thus  the  third  stage  begins.  The  tumor  now  appears  between  the 
lids  as  a  spongy,  bleeding  mass,  ulcerated  on  the  surface — exoph- 
thalmia  fungosa.  It  extends  also  in  the  optic  nerve  backward 
toward  the  cranial  cavity.  If  the  chiasm  becomes  involved  the 
blindness  may  be  bilateral.  The  fourth  stage,  that  of  metastasis, 
now  develops  in  the  neighboring  bones  and  lymph-glands.  In 
about   18  per  cent,  of  all  cases  a  glioma  develops  in  the  second 

^  The  name  •'Cat"s-eye"  is  sometimes  given  to  this.  In  the  cat,  light  is  reflected 
oatward  from  a  choroidal  layer  called  the  tapelum  cellulosum.  and  the  eye  may  shine  if 
the  pupil  is  wide  enough.  Blindness,  with  illumination  from  the  pupil,  may,  however, 
arise  from  other  conditions,  and  the  term  cat's-eye  should  not  be  used  as  a  synon\-m  for 
glioma  retina. 


320  DISEASES    OF    THE    RETINA    AND    OPTIC    NERVE. 

eye,  but  is  to  be  considered  as  an  independent  growth,  not  a 
metastasis. 

The  diagnosis  is  easy  after  the  second  stage  has  been  reached. 
There  may  be  some  confusion  in  the  first  stage,  most  commonly 
with  chronic  suppurative  choroiditis  (pseudo-glioma),  arising  often 
from  a  meningitis  or  cerebro-spinal  meningitis,  or  from  abscess  of 
the  vitreous.  It  should  be  observed  that  in  choroiditis  there  is 
first  inflammation  with  subsequent  blindness  ;  in  glioma  the  reverse 
is  the  case  ;  in  choroiditis  the  eye  is  soft,  in  glioma  hard ;  and  in 
glioma  the  ophthalmoscope  reveals  the  swollen,  protruding  nodules. 
If  a  diagnosis  is  impossible — supposing  the  eye  to  be  blind — it  is 
best  to  treat  it  as  if  a  glioma  were  present,  since  it  is  no  great 
calamity  to  enucleate  an  eye  already  blind,  but  to  neglect  or  to 
postpone  the  treatment  (enucleation)  in  glioma  may  cost  the 
patient  his  life. 

8.  INJURIES. 

Injuries  to  the  retina  are,  as  a  rule,  combined  with  injuries  to 
other  parts  of  the  eye,  and  are  therefore  mentioned  again  under 
Diseases  of  the  Eye  as  a  whole  {q.  v.).  Only  two  particular  varie- 
ties are  discussed  here. 

{a)  Commotio  Retinae  (Berlin). — After  an  injury  to  an  eye  by  a 
blunt  instrument  the  retina  becomes  cloudy  at  and  in  the  vicinity 
of  the  disc  at  first.  This  cloudiness  is  demonstrable  soon  after  the 
accident,  increases  during  the  next  day,  and  reaches  its  height  twen- 
ty-four to  thirty-six  hours  afterward,  subsiding  slowly  in  about  three 
days.    This  is  probably  due  to  an  edema  of  the  retina  dependent  upon 

hemorrhaore  between  choroid  and  sclera.  Visual  acuity  declines  to  — 

IS  .  .40 

or  — -,  light  perception  is  reduced,  and  there  are  dark  spots  in  the 

field  of  vision.  There  are,  besides,  other  signs  of  the  injury,  such 
as  hemorrhage  in  the  anterior  chamber,  contraction  or  dilatation  of 
the  pupil,  and  episcleral  injection. 

Prognosis  is  favorable.  Treatment  need  be  limited  to  a  mere 
removal  of  all  chance  of  irritation  to  the  eye. 

{b)  Dazzling. — An  eclipse  of  the  sun  can  be  looked  at  without 
danger  only  when  a  well-smoked  glass  or  an  arrangement  of  glasses 
of  complementary  colors  is  held  before  the  eye.  This  rule  is,  how- 
ever, again  and  again  neglected,  and  it  happens  after  every  eclipse 
that  the  ophthalmic  surgeon  is  consulted  by  patients  who  have 
been  injured  by  looking  at  the   sun  with   the  naked  eye.     They 


OPAQUE    NERVE    FIBERS.  321 

complain  that  there  is  a  dark  spot  before  their  eyes  and  that  they 
cannot  see  distinctly.  In  the  severer  cases  the  ophthalmoscope 
shows  a  grayish  spot  in  the  center  of  the  macula  lutea.  In  the 
eclipse  of  1890  Haab  saw  eight  such  cases  ;  in  three  of  them  the 
grayish  spot  was  a  true  optogram  of  the  sun,  on  which  could  be 
distinctly  seen  an  impression  corresponding  to  the  round  disk  of 
the  moon.  It  is  supposed  that  the  gray  spot  results  from  coagula- 
tion of  albuminous  corpuscles.  In  the  milder  cases  the  disturbance 
subsides,  but  in  the  severer  form  a  permanent  scotoma  remains. 
Treatment  consists  in  rest  and  confinement  in  a  dark  room. 


9.  CHANGES  DUE  TO  AGE. 

(rt)   In  the  lamina  vitrea  of  the  choroid,  see  p.  jo/. 

[d)  Senile  disease  of  the  macula  is  a  rather  common  occurrence,  and  destroys 
many  a  surgeon's  and  patient's  hope  of  the  success  of  a  cataract  operation.  It  consists 
of  bright,  yellowish-red  spots  lying  in  a  black  dotted  field.  These  spots  become  white 
later  on.  The  visual  disturbance  is  excessive,  much  greater  than  in  other  senile  changes 
near  the  macula  lutea. 

10.  MEDULLATED  (OPAQUE)  NERVE-FIBERS. 

These  are  almost  always  discovered  accidentally  by  the  ophthalmoscope,  since  they 
cause  no  symptoms  and,  at  least  in  the  vast  majority  of  cases,  no  visual  disturbances. 
An  eye  in  which  they  have  been  found  owes  its  subnormal  visual  acuity  to  refractive 
errors  or  other  pathological  conditions,  but  in  a  perimetric  examination  a  scotoma  or  an 
enlarged  Mariotte's  spot  will  be  discovered,  the  edges  of  which  correspond  to  the  area  of 
the  opaque  nerve-fibers. 

The  characteristic  ophthalmoscopic  image  is  the  following :  Upward  or  downward, 
seldom  inward,  and  very  rarely  outward,  from  the  papilla,  there  are  seen  white,  striated 
blotches  with  fringed  edges ;  these  take  preferably  the  direction  of  the  principal  vessels. 
They  may  be  confounded  with  pathological  changes  (fatty  deposits,  etc.),  only  when  they 
are  not  contiguous  to  the  disc  (an  exceptional  though  recorded  appearance),  but  are  sepa- 
rated from  it  by  a  distinct  interspace.  Even  then  the  reflection  from  the  nerve-fibers,  the 
striation,  and  the  flame-like  shape  of  the  figure  ought  to  be  characteristic  enough.  Retinal 
vessels  course  over  the  fibers,  or  sometimes  dip  in  among  them,  appearing  then  as  if 
broken  off.  The  phenomenon  arises  from  the  fact  that  part  of  the  fibers  of  the  optic 
nerve  retain  their  o]>aque  medullary  sheath  for  a  short  distance  after  passing  through  the 
lamina  cribrosa  of  the  sclera.  The  condition  is  an  anomaly  of  development,  and  is  usu- 
ally associated  with  some  abnormality  of  the  skull,  or  of  the  spinal  column,  and  with 
squint.      In  the  retina  of  the  rabbit,  medullary  nerve-fibers  are  normally  present. 

Parasites  are  discussed  later,  under  Entozoa. 


323  DISEASES    OF   THE    RETINA    AND    OPTIC    NERVE. 

B.  DISEASES  OF  THE  OPTIC  NERVE. 

1.  CHOKED  DISC  (Stauukgspapille). 
This  begins  with  an  indistinct  hyperemia  and  moderate  cloudi- 
ness of  the  edges  of  the  disc.  Gradually,  swelling  and  opacity  be- 
come evident  in  the  disc  and  its  immediate  neighborhood.  As  the 
disease  develops,  the  following  ophthalmoscopic  image  is  found  ■} 
The  papilla  seems  decidedly  larger  than  normal ;  it  projects  into  the 
vitreous,  as  may  be  proven  by  using  the  "  parallax  test "  in  examin- 
ing different  sections  of  the  same  vessel  {p.  ijj) ;  its  edges  are  ab- 
rupt, but  not  well  defined  against  the  surrounding  retina;  the  color 
is  reddish-white,  the  striations  spoke-like ;  the  arteries  are  narrow, 
and  indistinct  or  invisible  toward  the  disc ;  the  veins  are  dark,  di- 


«*>«MWR  itiBawr'/- 


■ —       Retina. 
Choroid 


Sderotic. 


Fig.  117. — Mebidiokal  Sectjok  through  a  Chokkd  Disc    (,A/ier  P^geusteckrr  mmd  G^nth.) 
The  sweUiog  subsides  abruptly  at  the  rigbt,  gradually  at  the  left. 

lated,  and  tortuous,  beginning  at  the  disc  with  a  pale-pointed  end  ; 
at  times  small  hemorrhages  are  present  at  the  edge  of  the  disc. 

After  this  condition  has  lasted  a  long  time,  often  for  months, 
there  begins  a  gradual  recession,  characterized  by  increasing  pale- 
ness and  flatness  of  the  disc. 

Choked  disc  of  itself  does  not  cause  visual  disturbance.  It  is 
due  less  to  inflammatory  round-cell  infiltration  than  to  the  dilata- 
tion of  the  vessels,  the  saturation  with  serum,  and  the  thickening 
(hypertrophy)  of  the  non-medullated  ner\'e-fibers.  The  most  recent 
investigations  hav^e,  however,  shown  that  actual  inflammation  is 
never  quite  lacking ;  in  any  case  there  is  bound  to  be,  sooner  or 
later,  an  infiltration  with  round  cells  and  hypertrophy  of  interstitial 
tissue  {Fig.  iif).     This  new-formed  tissue  finally  shrinks  and  by  its 


^  Fig.  J 14,  p.  jog,  papllitis  nepbridca,  gives  at  the  same  time  a  good  illustration  of  a 
choked  disc. 


CHOKED    DISC.  323 

pressure  causes  the  atrophy  of  the  nerve-fibers.  Impairment  of 
vision  is  the  result,  passing  slowly  into  total  blindness.  This  im- 
pairment is  detectable  as  : — 

(1)  Diminution  of  central  visual  acuity; 

(2)  Contraction  of  tlfe  visual  field,  unsymmetrical ; 

(3)  Color  blindness  or  dullness. 

Diminished  visual  acuity  comes  gradually,  but  may  be  occasion- 
ally exaggerated  by  attacks  of  amblyopia,  or  even  of  blindness, 
which  may  not  always  subside  completely. 

Choked  disc  is  almost  always  bilateral  and  usually  the  result  of 
a  brain  tumor. 

There  has  been  j^enty  rf  discussion  concerning  the  relatioa  between  a  tmnor  in  the 
cerebral  cortex,  or  even  in  the  cerebelltnn,  and  choked  disc.  Jnst  at  present  two  theories 
contest  for  the  honor  of  being  the  only  satisfactory  explana- 
tion— the  mechanical  and  the  inflammatory  theory.  Accord- 
ing to  the  mechanical  explanation  the  tmnor  raises  the  accus- 
tomed pressure  in  the  skull ;  cerebrospinal  fluid  is  consequently 
driven  forward  between  the  sheaths  of  the  optic  nerve  and  a 
"  hydrops  of  the  nerve  sheaths  "  is  produced  (/%".  118).  The 
serous  saturation  of  the  nerve -fibers,  once  they  reach  the  con- 
stricted network  of  the  lamina  cribrosa,  jwodnces  a  pressure 
that  prevents  the  return  of  the  venous  blood,  and  thereby  pro- 
duces the  stasis.  This  theory  seems  to  be  continually  losing 
ground  before  the  inflammatory  theory.  Numerous  pathological 
examinations  have  shown  that  choked  disc  is  a  regular  and  early 
sign  of  simple  inflammation  in  the  head  of  the  optic  nerve ; 

that  histological  evidence  of  inflammation  is  regularly  found,  rizn.  with  Htdkops  of 

not  only  in  the  optic  nerve  head,  but  also  in  the  optic  nerve  T""    *^ '"^-LSs'^^"^" 

^  »  '  '^  SHEATHS.  \AjteT  ragen- 

itself,  in  its   membranes,  and  even  at   times    in    the    retina.  sUcke-r  and  Gmtk.) 

Now,  to  establish  the  relation  between  the  inflammation  with 

inflammatory  edema — that  is,  between  the  causative  brain  lesion  and  the  choked  disc — 
the  assxmiption  is  made  that  germs  or  some  chemically  acting  material  is  carried  by  the 
l3rmph- current  from  the  brain  to  the  papilla,  where  its  destructive  influence  is  developed. 

This  inflammatory  theory  does  not,  however,  explain  everything.  Particularly  does 
it  leave  unsolved  the  question  why  the  inflammation  of  the  optic  nerve  head  is  so  regu- 
larly productive  of  choked  disc  when  the  causative  lesion  is  a  new  growth  in  the  brain, 
but  is  only  exceptionally  so  productive  when  this  inflammation  of  the  optic-ner^-e  can  be 
traced  to  a  parasite  in  the  brain,  to  a  cysticercus  or  an  echinococcus,  to  hydrocephalus,  to 
a  brain  injury  or  abscess,  or  to  any  other  inflammation  of  the  contents  of  the  skull. 

Unilateral  choked  disc  is  usually  caused  by  tumor  or  inflammation  within  the  orbit. 
The  diagnosis  is  easy,  since  there  is  present,  in  addition  to  the  onesidednessof  the  fondus 
change,  the  condition  of  exophthalmos  on  that  side.  It  must  be  borne  in  mind  that  in 
rare  cases  retinitis  albuminurica  (/.  308)  runs  its  course  with  the  signs  of  choked  disc 

Prognosis  is  unfavorable.  Cerebral  tumors  generally  end  in 
death  after  months  or  years.     The  picture  may  meanwhile  change 


324  DISEASES   OF   THE   RETINA   AND    OPTIC    NERVE. 

from  that  of  choked  disc  to  that  of  optic-nerve  atrophy.  New 
growths  lying  on  the  surface  and  admitting  of  accurate  localization 
may  be  reached  by  operative  treatment. 

Treatment. — If  the  new  growth  is  a  syphilitic  gumma,  mercury 
and  iodid  of  potassium  may  effect  a  transient  if  not  a  lasting  cure. 
The  choked  disc  will,  of  course,  subside,  but  the  visual  acuity  will 
be  permanently  impaired. 

2.  INFLAMMATION  OF  THE  OPTIC  NERVE  (Neuritis  Optica, 

Papillitis). 

It  is  not  always  possible  to  distinguish  this  disease  from  choked 
disc  by  the  ophthalmoscope.  In  neuritis  optica  the  papilla  is  seen 
to  be  swollen  and  clouded  {Fig.  114).  The  swelling  is  less  than  in 
choked  disc,  and  consequently  extends  further  and  in  a  flatter  man- 
ner into  the  retina,  so  that  the  observer  misses  the  decided  effect^ 
of  a  prominence.  The  arteries  are  only  slightly,  or  not  at  all,  con- 
tracted, the  veins  are  dilated  and  tortuous.  If  the  opacity  extends 
noticeably  into  the  retina,  usually  along  the  vessels,  the  condition 
is  called  papilloretinitis.  In  chronic  papilloretinitis  hemorrhages 
and  white  s|x>ts  are  found  in  the  retina,  an  appearance  similar  to 
that  of  retinitis  albuminurica.  Confusion  may  be  easily  avoided, 
however,  by  observing  that  in  neuritis  optica  the  more  intense 
changes  are  seen  at  the  disc,  while  in  neuritis  albuminurica  thej' 
usually  are  greatest  in  the  retina.  In  doubtful  cases  the  necessary 
examination  of  the  urine  will,  of  course,  decide. 

In  many  cases  there  are  seen  along  the  vessels  jjeculiar,  glitter- 
ing reflexes  that  move  as  the  mirror  is  rotated  and  give  a  satin- 
like appearance  to  the  fundus.  The  phenomenon  maybe  observed 
in  children  having  no  pathological  manifestations,  but  it  is  always 
suspicious  if  there  is  any  visual  weakness  in  addition. 

The  visual  disturbances  (amblyopia,  constriction  of  the  field  of 
vision,  impaired  color-sense)  differ  in  different  cases  and  have  no 
exact  relationship  to  the  visible  objective  changes.  The  disease 
affects  the  entire  optic  nerve,  while  the  ophthalmoscope  can  give 
us  information  only  of  the  peripheral  end  of  it  It  is  a  general  rule 
that — 

(i)  Visual  disturbances  app>ear  earlier  than  in  choked  disc,  and 

(2)  The  disease  leads  to  atrophy  of  the  nerve  and  to  blindness 
oftener  than  does  choked  disc. 

Inflammation  of  the  optic  nerve  is,  in  the  majority  of  cases,  an 


INFLAMMATION    OF   THE   OPTIC    NERVE.  325 

extension  from  some  lesion  of  the  brain  and  its  membranes;  it  was 
therefore  called  by  Graefe  neuritis  descendens..  Tubercular  basilar 
meningitis  of  children,  epidemic  cerebrospinal  meningitis,  menin- 
gitis from  suppurative  otitis  and  from  other  infectious diseases.may 
all  be  considered  causes.  Infectious  diseases,  syphilis,  and  sys- 
temic intoxications  may  cause  an  optic  neuritis  directly. 

The  pathological  evidence  differs  according  to  the  cause.  In 
tubercular  basilar  meningitis,  tubercles  have  been  found  in  the  three 
membranes  of  the  nerve.  In  suppurative  meningitis  the  character- 
istic is  an  abundance  of  pus  cells  in  the  intermembranous  spaces 
and  in  the  connective  tissue  of  the  optic  nerve.  In  syphilitic  neu- 
ritis there  is  an  extraordinary  thickening  of  the  optic  nerve,  occa- 
sioned by  hypertrophy  and  cell  infiltration  of  the  interstitial  con- 
nective tissue  and  of  the  pial  sheath. 

Besides  these  optic-nerve  inflammations  from  a  known  cause, 
there  are  others,  the  cause  of  which  is  unknown.  To  these  belong 
"  neuritis  from  heredity."  It  is  a  fact  that  the  members  of  many 
families  (males  particularly)  are  attacked  between  the  eighteenth  to 
twenty-fourth  years  by  a  bilateral  optic  neuritis  from  no  apparent 
cause.  The  parents  may  be  quite  healthy,  and  there  is,  therefore, 
no  direct  heredity.  Even  if  there  were,  it  would  but  throw  the 
question  one  generation  back,  not  answer  it.  "  Optic  neuritis  from 
cold  "  is  quite  as  obscure,  and  also  "  optic  neuritis  from  suppression 
of  the  menses."  With  the  innumerable  cases  of  "catching  cold," 
and  the  rarity  of  an  attendant  optic  neuritis,  suspicion  must  be 
aroused  that  it  is  an  already  affected  (latent)  optic  nerve,  which  re- 
sponds to  the  cold  by  becoming  inflamed. 

There  are,  too,  cases  of  neuritis  optica  in  which  not  even  a  cold 
or  such  an  intangible  cause  can  be  detected.  Leber's  opinion  is 
that  the  condition  probably  rests  upon  a  latent  meningitis.  There 
have  recently  been  reported  several  cases  of  optic  neuritis  appear- 
ing in  young  mothers  during  the  weaning  period.  The  assump- 
tion has  been  made  from  this  that  during  the  secretion  of  milk 
some  poisonous  albuminoid  by-product  has  been  originated,  which 
caused  an  optic  neuritis  by  autoinfection  of  the  mother. 

Prognosis  is  doubtful ;  cures  with  restoration  of  normal  visual 
acuity,  cures  with  amblyopia  of  every  degree,  and,  finally,  a  lapse 
into  total  blindness  have  all  happened. 

Treatment  must  depend  on  the  cause.  If  this  is  not  discover- 
able, diaphoresis  or  mercury  and  iodid  of  potassium  may  be  tried. 


326  DISEASES    OF   THE    RETINA    AND    OPTIC    NEKVE. 

Some  claim  good  effects  from  blood-letting  from  the  temporal  or 
mastoid  region  by  means  of  Heurteloup's  artificial  leech.  The  re- 
ports of  results  of  such  treatment  encourage  the  suspicion  that  mild 
cases  may  get  well  of  themselves. 

3.  RETROBULBAR  NEURITIS. 

If  the  optic  nerve  beyond  the  bulbus  becomes  inflamed,  the  disc 
is  not  necessarily,  certainly  not  immediately,  involved.  At  the 
commencement  of  a  retrobulbar  neuritis  the  fundus,  therefore,  ap- 
pears normal,  or,  at  the  most,  slightly  hyperemic  with  moderate 
haziness  of  the  edges  of  the  disc.  At  a  later  stage  of  the  disease 
there  is,  however,  a  very  characteristic  ophthalmoscopic  image,  that 
is,  a  discoloration  of  the  temporal  halves  of  the  papillae,  where  the 
grayish-white  is  in  sharp  contrast  to  the  dull  red  of  the  smaller 
nasal  halves.  This  atrophy  may  advance  so  far  that  the  lamina 
cribrosa  of  the  sclera  becomes  visible. 

Under  certain  circumstances  the  diagnosis  may  be  made  solely 
from  the  subjective  symptoms,  they  being  often  quite  characteristic 
enough  for  this  purpose.  The  patient  complains  that  he  sees  poorly, 
especially  in  bright  daylight,  but  somewhat  better  in  a  dimmer  light 
{iiyctalopid).  If  the  examination  is  made  by  test-type  and  perimeter, 
the  reduction  in  visual  acuity  will  be  found  to  depend  upon  a  sco- 
toma at  the  center  of  the  retina,  and  that  peripheral  vision,  and 
particularly  the  extent  of  the  field,  is  quite  or  nearly  normal.  At 
first  there  is  only  a  color  scotoma,^  within  this  spot  green  and  red 
appearing  gray.  As  the  disease  advances,  the  extent  of  the  color 
as  well  as  the  light  scotoma  increases,  until,  finally,  there  is  an 
"  absolute  "  dark  spot.  Fixation  then  becomes  impossible,  the  eye 
makes  uncertain  movements  hither  and  thither,  and  nystagmus  re- 
sults. The  field  of  vision  may  be  gradually  obliterated  and  the  dis- 
ease end  in  blindness. 

The  nature  of  the  disease  consists  of  an  inflammatory  hypertro- 
phy of  connective  tissue  which,  by  its  later  cicatricial  contraction, 
causes  an  atrophy  of  the  nerve-fibers.  Uhthoffsays  that  all  fibers 
of  a  diseased  nerve  do  not  perish.  At  first  the  disease  is  confined 
to  the  papillomacular  fibers  {p.joj)  ;  it  is  usually  bilateral,  attack- 
ing with  great  preference  men  in  the  prime  of  life.     It  may  be  either 


^  Brauchlis  states  that  besides  the  central  color  scotoma  there  is  regularly  a  contrac- 
tion of  the  field  for  colors. 


ATROPHY.  327 

acute,  in  which  case  blindness  may  be  the  result  after  a  few  days  ; 
or  chronic,  and  then  weeks,  months,  or  years  may  pass  before  the 
patient  seeks  medical  advice.  In  the  acute  form  there  is  often  a 
complaint  of  pain  deep  within  the  eye,  on  moving  the  eye  or  from 
pressure  upon  it. 

As  causes  of  neuritis  retrobulbaris  may  be  mentioned  :  acute 
infectious  diseases,  syphilis,  lead  poisoning,  cold  (?),  but  all  these 
together  are  not  such  disastrous  agents  as  the  abuse  of  tobacco  and 
alcohol.  The  disease  is,  therefore,  often  called  tobacco  or  alcohol 
amblyopia,  or  intoxication-ainblyopia} 

As  a  rule,  both  tobacco  and  alcohol  are  used  and  abused  together, 
but  either  one  may  cause  the  trouble. 

The  prognosis  is  favorable  in  so  far  as  it  is  possible  in  recent 
cases  to  promise  complete  recovery  to  patients  who  agree  to  give 
up  their  bad  habits;  it  is  unfavorable  because  one  of  the  worst 
results  of  continued  abuse  of  alcohol  is  to  depress  the  strength  of 
the  will.  Patients  soon  relapse,  therefore,  when  they  have  noticed 
improvement  after  some  time  of  self-denial,  and  after  the  specter  of 
blindness  seems  to  have  been  laid  for  the  moment.  It  is  remark- 
able, however,  that  even  after  a  relapse  from  grace  the  patient's 
symptoms  of  neuritis  do  not  always  come  back  again. 

Treatment  need  not  be  local ;  abstinence  from  tobacco  and 
alcohol  is  quite  sufficient.  The  usual  accompanying  chronic  gas- 
tritis must  be  treated,  since  most  all  drinkers  suffer  from  it,  and 
since  it  is  often  the  exciting  cause  of  the  breaking  out  of  the  disease. 
In  those  few  cases  of  retrobulbar  neuritis  due  to  other  influences 
the  rules  of  treatment  given  on  /.  ^2^  should  be  followed. 

4.  ATROPHY. 2 
The  visual  power  of  an  eye  is  destroyed  if  the  fibers  of  the  optic 
nerve  in  any  place  become  atrophied  and  incapable  of  function- 
ating. As  far  as  vision  is  concerned,  it  is  a  matter  of  indifference 
whether  the  atrophy  occurs  within  the  orbit  or  in  the  optic  canal. 
This  is  by  no  means  so  of  the  ophthalmoscopic   image !     If  the 

^  Many  authors  distinguish  between  into.xicatlon-amblyopia  and  a  retrobulbar  neuritis 
from  other  causes. 

*  Atrophy  really  signifies  "  not  nourished,"  but  the  characteristic  of  atrophy  is  diminu- 
tion in  the  size  of  the  elements.  The  word  atrophy  is  also  (not  quite  correctly)  used  to 
designate  the  condition  which,  from  a  standpoint  of  pathological  anatomy,  ought  to  be 
called  degeneration. 


328  DISEASES    OF    THE    RETINA    AND    OPTIC    NERVE. 

papilla  becomes  inflamed  and  subsequently  atrophies,  the  ophthal- 
moscope reveals  a  condition  recognizable  as  a  disappearance  of 
nerve-fibers  and  a  simultaneous  deposit  of  new-formed  and  subse- 
quently contracted  connective  tissue.  If,  on  the  other  hand,  the 
interruption  in  the  path  of  the  optic  nerve  is  due  to  inflammation, 
injury,  or  pressure  upon  the  nerve  behind  the  eyeball,  the  papilla 
appears  quite  unchanged  at  first,  and  only  gradually  assumes  the 
atrophic  look,  because  the  disappearance  of  the  nerve-fibers  has 
taken  place  only  at  the  inflamed,  injured,  or  compressed  spot,  and 
only  gradually  passes  down  to  the  papilla  {atrophia  desceyidens). 
The  appearance  of  the  papilla  is,  however,  not  the  same  as  in  papil- 
lary atrophy,  because  at  the  papilla  there  is  in  the  former  case 
only  the  disappearance  of  the  nerve-fibers  and  blood-vessels,  new- 
formed  connective  tissue  being  altogether  absent. 

Besides  papillary  and  descending  atrophy,  there  is  a  simple  atro- 
phy, in  which  there  has  been  no  inflammation  of  any  part  of  the 
optic  nerve  at  all.  The  condition  might  be  called  essential  atrophy, 
that  is,  a  disappearance  of  the  medulla  of  the  nerve  and  a  destruc- 
tion of  the  function  of  the  axis-cylinder.  Such  a  nerve  appears 
gray  and  shimmery — gray  degeneration — and  is  associated  with 
corresponding  changes  in  certain  tracts  of  the  brain  and  spinal 
cord.  This  third  form  presents  the  same  image  to  the  ophthalmo- 
scope as  does  the  descending  atrophy.  An  ascending  atrophy  is 
possible,  for  supposing  the  retina  to  become  incapable  of  function- 
ating, the  optic  nerve  would  undoubtedly  degenerate,  and  the  pa- 
pilla would,  after  a  time,  give  evidence  of  a  pure  atrophy,  assuming, 
of  course,  that  the  papilla  is  still  visible  and  is  not  associated  with 
the  retina  in  the  disease.  For  example,  after  embolus  of  the  cen- 
tral artery  there  is  regularly  a  simple  atrophy,  and  after  albumin- 
uric retinitis  a  similar  condition  has  been  frequently  observed. 

What  are  the  ophthalmoscopic  differences  between  papillary 
atrophy  and  simple  or  descending  atrophy?  The  color  and  the 
presence  or  absence  of  "  atrophic  excavation  "  {q.  v.).  In  papil- 
lary atrophy  we  find  the  nerve-sheath  whitish,  its  edge  hazy,  par- 
ticularly on  the  nasal  side,  at  times  also  irregular  ;  there  is  no  dif- 
ference in  the  level  (/.  ijj)  between  papilla  and  retina;  the  lamina 
cribrosa  is  not  visible  ;  the  retinal  vessels  are  narrow.  (If  the  papil- 
lary atrophy  follows  a  retinitis  pigmentosa  or  a  choroiditis  syph- 
ilitica, the  disc  appears  grayish-yellow  and  waxy.) 

In  uncomplicated  or  simple  atrophy  the  disc  is  of  a  pure  white 


SIMPLE    ATROPHY.  329 

or  bluish-white  color.  Since  the  space  left  open  by  the  disappear- 
ance of  the  nerve-fibers  is  not  occupied  by  any  new-formed  connec- 
tive tissue,  the  disc  appears  sunken,  excavated,  and  allows  the  net- 
work of  the  lamina  cribrosa  to  be  seen.  The  disc  is  round,  regu- 
larly and  sharply  outlined.     The  retinal  vessels  are  at  first  normal. 

After  this  description  it  is  best  to  study  from  a  clinical  stand- 
point— 

(a)  Simple  atrophy,  and 

(d)  Descending  atrophy. 

(a)  Simple  atrophy,  called  also  pi'ogressive  amajirosis.  The 
patient  notices  an  early  disturbance  in  vision,  because  the  condi- 
tion is  a  bilateral  affection.  Examination  shows  that  this  disturb- 
ance consists  of  diminution  in  central  visual  acuity  and  of  contrac- 
tion of  the  visual  field.  The  form  of  the  latter  varies  considerably, 
being  in  one  case  concentrically  contracted,  in  another  strewn  with 
irregular  scotomata  ;  as  a  rule,  the  outer  and  upper  parts  of  the  field 
of  vision  are  more  contracted  than  the  inner  and  lower  parts. 
Color-sense  is  early  affected,  green  being  lost  first,  then  red,  then 
yellow,  blue  last.  Light-sense  is  longest  retained.  The  end  is 
total  blindness.  Objectively,  the  papilla  is  seen  to  be  either  gray 
or  quite  white.  This  appearance  goes  hand  in  hand  with  the  decline 
of  visual  acuity  and  the  contraction  of  the  visual  field,  or  may  even 
precede  these  disturbances  of  function.  There  must,  then,  be  some 
system  disease  in  which  the  nerve-fibers  are  equally  attacked  in 
their  entire  course.  In  descending  atrophy  the  condition  is  obvi- 
ously reversed;  here  the  change  in  the  disc,  demonstrable  by  any 
objective  examination,  is  not  visible  for  months  or  years  after  the 
disturbances  of  function. 

The  great  majority  of  all  cases  is  due  to  some  disease  of  the 
brain  or  spinal  cord,  especially  of  syphilitic  origin  :  in  the  brain, 
disseminated  sclerosis,  progressive  paralysis, and  general  paralysis; 
in  the  spinal  cord,  tabes  dorsalis.^ 

It  is  necessary,  therefore,  to  make  a  thorough  examination 
of  the  brain  and  cord  whenever  optic-nerve  atrophy  is  dis- 
covered, and  the  neurologist  should  be  consulted  to  evolve  order 
out  of  the  chaos  of  paralysis,  anesthesia,  paresthesia,  and  hyper- 
esthesia.   In  tabes,  optic-nerve  atrophy  is  not  apparent  until  the  dis- 

1  The  nature  of  the  relation  l:)etween  diseases  of  the  cord  and  brain  on  tlie  one  side, 
and  optic-nerve  atrophy  on  the  other,  is  not  exacily  known. 


330  DISEASES    OF   THE    RETINA    AND   OPTIC    NERVE. 

ease  of  the  cord  has  betrayed  itself  by  other  signs  and  symptoms; 
the  "  Hghtning  pains,"  the  loss  of  patellar  reflex,  unevenness  of  the 
pupils,  and  ataxic  gait,  for  example.  In  progressive  paralysis,  on 
the  contrary,  the  optic-nerve  atrophy  is  said  occasionally  to  be  the 
first  sign,  although  even  in  such  cases  a  careful  examination  may 
bring  to  light  various  mental  symptoms,  such  as  hypochondria, 
irritability,  weakness  of  judgment  and  of  memory.  In  a  number  of 
cases  of  progressive  atrophy  of  the  optic  nerve  no  brain-  or  cord- 
lesion  can  be  discovered,  and  the  eye-lesion  must  be  considered  as 
idiopathic.  Catching  cold  (??),  excesses,  undue  physical  and  men- 
tal effort  and  excitement,  as  well  as  syphilis,  have  all  been  called 
causes. 

Treatment  is  unsuccessful,  the  prognosis  hopeless.  The  con- 
tinuous electric  current  is  said  to  have  stopped  and  improved  the 
disease,  but  nothing  has  as  yet  prevented  it  from  resulting  in  total 
blindness, 

(d)  Descending  atrophy  requires  the  more  time  to  reach  the  pa- 
pilla and  to  make  itself  visible,  the  more  central  its  origin  and  the 
older  the  affected  individual.  For  example,  if  a  lesion  of  softening 
attacks  the  optical  centers  in  the  cerebral  cortex,  the  atrophy  de- 
scends through  the  "  optic  radiation  "  {.Fi^.  iij,  p.  joj)  into  the 
external  geniculate  body,  which,  as  Monakow  has  shown,  disap- 
pears so  rapidly  that  even  with  the  naked  eye  its  decrease  in  size 
can  be  detected.  Further  on,  the  atrophy  attacks  the  optic  tract, 
chiasm,  and  nerve,  and  after  years  becomes  visible  at  the  disc,  if 
the  patient  does  not  die  meanwhile.  If  the  causative  disease  is  on 
the  optic  nerve  itself,  where  it  passes  through  the  canalis  opticus, 
descending  atrophy  may  become  visible  at  the  disc  within  a  few 
weeks.  A  descending  atrophy  which  has  become  visible  to  the 
ophthalmoscope  is,  as  a  rule,  therefore  traceable  to  some  disease 
within  the  orbit,  at  the  canalis  opticus,  or  at  the  base  of  the  brain. 
Witliin  the  ordit  there  may  be  injuries  or  tumors.  The  diagnosis  is 
supported  if  the  atrophy  is  unilateral,  if  there  is  a  history  of  an 
accident  in  one  case,  or  an  exophthalmos  in  another.  Af  tJie 
canalis  opticus  syphilitic  ostitis  and  periostitis  may  so  contract  the 
aperture  that  the  nerve  atrophies  on  account  of  the  pressure.  At 
the  base  of  the  brain  inflammations  of  the  sphenoid  bone  or  aneu- 
rysms of  the  internal  carotid  artery  may  interrupt  the  transmission 
of  optic  impressions,  and  hemorrhage  near  the  external  geniculate 
body  may  lead  to  softening  of  the  primary  optical   centers.     Of 


THE    LENS.  33  [ 

course,  such  lesions  will  occasion  other  disturbances  of  function 
besides  those  of  sight,  and  the  combination  of  all  the  symptoms 
will  aid  in  the  localization  of  the  disease. 

It  deserves  mention  that  blindness,  or  at  least  a  high  degree  of 
amblyopia,  occasionally  develops  after  severe  hemorrhage,  particu- 
larly from  the  stomach  ;  the  ophthalmoscope  shows  a  disc,  normal 
at  first,  but  after  some  weeks  manifesting  the  characteristic  signs 
of  atrophy.  The  cause  of  this  evident  atrophy  is  explained  by 
many  observers  as  a  fatty  degeneration  ;  others  consider  it  as  an 
interstitial  inflammation  of  a  retrobulbar  part  of  the  optic  nerve. 

The  prognosis  is  not  quite  so  bad  as  it  is  in  simple  atrophy,  since 
many  diseases  that  may  cause  descending  atrophy,  as  syphilitic 
periostitis,  for  example,  are  amenable  to  treatment.  Atrophic  nerve- 
fibers  cannot,  to  be  sure,  be  restored,  but  the  progress  of  the  atrophy 
may  be  cut  short,  and  the  visual  acuity  yet  remaining  will  thereby  be 
preserved. 


DISEASES  OF  THE  LENS. 

INTRODUCTION. 

The  lens,  lens  crystallinea,  consists  of  a  transparent  material  enclosed  in  an  equally 
transparent,  homogeneous  capsule.  Its  posterior  surface  rests  against  the  vitreous  in  the 
fossa  patellaris  ;  its  anterior  surface  rests  against  the  posterior  surface  of  the  iris  {Fig.  4,  p. 
2y).  The  lens  possesses  an  anterior  [b)  and  a  posterior  (r)  pole  {Fig.  4g,  p.  118),  and  an 
equator  {d).  At  the  anterior  pole  the  capsule  has  a  thickness  of  0.016  vim.,  at  the  pos- 
terior pole  only  half  as  much.  The  diameter  of  the  equator  amounts  to  about  9  inni.  ;  the 
distance  of  anterior  pole  from  posterior  pole,  that  is,  the  thickness  of  the  lens,  is  about  4  vim. 

The  first  evidence  of  the  lens  in  the  embryo  consists  of  a  thickening  of  the  epiblast 
above  the  primary  optic  vesicle  {Fig.  tig).  This  collection  of  epithelial  cells  grows 
inward  and  depresses  a  thin  layer  of  the  mesoblast  and  the  anterior  wall  of  the  primary 
optic  vesicle.  The  lens  is  now  hollow,  its  wall  consisting  of  epithelial  cells.  The  cells  of 
the  posterior  wall  grow  forward  into  the  long  lens-fibers  hexagonal  on  cross-section, 
which  carry  the  nucleus  {Fig.  120)  forward  along  with  them.  Gradually  the  hollow  of 
the  lens  vesicle  disappears  and  the  lens  now  consists  of  the  original  posterior  epithelial 
cells  changed  into  lens-fibers,  and  the  original  anterior  cells  still  epithelial  in  character. 

The  lens  capsule  is  developed  at  the  same  time  and  is  considered  by  some  as  a  deriva- 
tive of  the  mesoblast,  by  others  as  a  cuticular  formation  from  the  epithelial  or  lens-cells. 
The  development  of  the  lens  is  not  completed  at  birth,  but  continues  till  about  the  twenty- 
fifth  year,  during  which  time  the  change  at  the  equator  from  epithelial  cells  to  lens- 
fibers  is  still  in  progress.     The  anatomical  and  physical  results  are  explained  on  p.  jg. 

From  the  above  it  is  obvious  that  only  the  anterior  capsule  is  covered  with  epithelial 
cells,  and  that  the  normal  posterior  capsule  has  no  such  covering.  1 

^  Pathologically  epithelioid  cells  are  found  on  the  surface  of  the  posterior  capsule. 


332 


DISEASES    OF   THE    LENS. 


The  lens-fibers,  each  confined  to  its  own  layer,  pass  from  the  anterior  toward  the  pos- 
terior pole.  All  the  fibers  of  one  layer  do  not  unite  at  one  single  point,  but  pass  rather 
along  certain  lines,  thus  producing  the  so-called  sutures  at  the  lenticular  poles,  visible  in 

the  hardened  lens  as  a  triradiate  figure. 
In  the  new-born  this  is  in  the  shape  of  a 
Y,  but  in  later  life  is  much  more  compli- 
cated owing  to  various  branched  pro- 
cesses that  follow  no  definite  path.  The 
anterior  triradiate  figure  can,  in  elderly 
persons,  be  beautifully  seen  by  means  of 
a  lens  and  focal  illumination. 

The  lens  in  the  adult  by  no  means 
remains  f)ermanently  in  the  same  con- 
dition. Rather  is  there  a  continuous 
change  going  on,  which  may  be  called  a 
nuclear  sclerosis  {see  p.  j8).  This  is  a 
change  in  the  oldest  and  innermost  fibers, 
which  from  early  youth  have  been  grow- 
ing denser  and  losing  their  water  constituent,  while  at  the  same  time  the  newer  layers  of 
the  lens  periphery  are  attacked  by  this  sclerosis  ;  the  nucleus  is  constant,  therefore,  but 
the  outer  part  of  the  lens  decreases.  It  may  happen  that  the  entire  contents  of  the  lens- 
capsule  hardens  into  a  homogeneous  suiistance.     A  sclerosed  nucleus  looks  like  amber. 


Fig.  119.' 


StaU:o/'tke  Optic  t^estdr 
' Primary  flpfirilRSlde 

VpiMui. 


-Beginning  op  the  Eve  in  a  Chick. 

(After  Koeliicker.) 


Memirarui,  ■      -t;v''': 
pupazaris        't'A'i 
CorneO'      ' 

ATvieroorc^iajnier-  ^  v'"' 1  "x 
£et£na..inner(zu/er    -  - 

Xeima,  cuter  iai/er.  -- ' 


\^A  "N^^^^  •■^■^"  ~  lens  ZpithdiuM' 

■■        L^l'i^-  Tvtreoics. 

'  Optic  JTerve 

-   ATierioyPu/aloidt 


Fig.  I20. — Development  of  the  Lens  in  a  Cat.     (After  a  preparation  by  Prof.  Stoehr ,  with  one 

change.) 

The  color  is  the  darker,  the  denser  and  harder  the  nucleus.  In  a  large  nucleus  it  may  be 
reddish- brown,  and  if  the  entire  lens  is  sclerotic,  even  dark  brown.  ^  The  color  of  the 
nucleus  perceptible  by  focal  illumination  gives  some  clue  to  the  size  of  the  cataract. 


1  Obviously  the  visual  acuity  is  then  extremely  reduced.  This  condition  is  called  black 
cataract  (cataracta  ni.qra)  in  distinction  to  (gray)  cataract.  In  a  gray  cataract  the  pupil 
looks  whitish-gray  when  light  is  thrown  into  it,  but  looks  black  in  a  black  cataract.   The 


CATARACT.  333 

The  Zonula  of  Zinn  (/)>.  4, p.  sj,  and  Fi^.  gjip.  2^4)  (Ligamentum  suspensorium 
lends)  serves  to  retain  the  lens  in  place ;  it  is  a  transparent,  fibrous,  perforated  mem- 
brane, stretched  between  the  processus  ciliares  and  the  lens,  passing  gradually  into  the 
lens  capsule,  partly  in  front  of,  partly  behind,  partly  at,  the  equator.  Between  the  folds 
of  the  zonula  is  the  canal  of  Petit  ^  encircling  the  equator.  This  canal  is  supposed  to  be 
filled  with  a  fluid  that  assists  the  nutrition  of  the  lens.  This  nutritive  fluid,  according  to 
Magnus,  surrounds  the  lens  in  two  engirdling  zones,  one  close  in  front  of,  the  other  close 
behind  the  equator.  Lymphatics  are  said  to  enter  at  the  posterior  pole,  and  to  find  their 
exit  near  the  anterior  pole,  the  evidence  being  based  on  pathological  observations. 


I.  CATARACT.2 

Any  pathological  change  in  the  lens  diminishes  its  transparency. 
As  soon  as  the  smallest  area  of  the  lens  loses  this  transparency  we 
call  it  cataract.  Opacities  in  the  capsule  are  called  capsular  cata- 
ract, opacities  in  the  lens  substance  are  called  lenticidar  cataract. 

A  lenticular  cataract  may  be  either  cortical  or  nuclear.  If  both 
cortex  and  nucleus  are  involved,  we  speak  of  complete  cataract.  If 
cataract  is  in  connection  with  or  is  the  result  of  other  eye  diseases, 
it  is  called  cataracta  complicata  ;  if  there  are  adhesions  between  iris 
and  ciliary  body  on  the  one  side  and  the  diseased  lens  on  the  other, 
we  call  the  condition  cataracta  accreta. 

What  influence  has  such  an  opacity  on  the  visual  acuity?  Often 
no  influence,  often  a  very  important  one,  much  depending  on  the 
size,  location,  and  nature  of  the  opacity.  For  example,  opacities 
lying  in  the  periphery,  and  covered  by  the  iris,  cause,  as  a  rule,  no 
disturbance  whatever.  It  must  not  be  forgotten  that  the  pupil  is 
at  one  time  dilated  and  at  another  contracted,  and,  therefore,  the 
saine  opacity  may  at  one  time  be  noticeable  and  at  another  be  al- 
together without  influence.     The  influence  of  the  intensity  of  the 

pupil  in  black  cataract  cannot  be  illuminated  with  the  ophthalmoscope,  the  light  being  so 
completely  absorbed  by  the  lens  that  it  is  neither  reflected  outward  nor  allowed  to  pass 
through  onto  the  retina,  as  it  does  normally. 

1  Some  authors  ignore  this  canal  of  Petit,  and  apply  the  name  to  certain  bulgings  of 
the  posterior  chamber.  Others,  again,  call  the  canal  of  Petit  the  space  between  vitreous 
and  posterior  surface  of  the  zonula. 

^  The  name  cataract  (waterfall)  comes  from  the  mistaken  notion  as  to  the  nature  of 
the  condition,  which  was  current  nearly  to  the  end  of  the  last  century.  It  was  thought 
that  cataract  was  caused  by  some  fluid  falling  in  front  of  the  lens  and  gradually  harden- 
ing into  a  membrane.  The  German  word  Star  is  derived  from  the  same  source  as  our 
stare,  criginally  stiflf. 


334  DISEASES    OF    THE    LENS. 

illumination  may  be  analogously  explained.  Many  patients  see 
better  in  a  dim  light ;  these  are  cases  with  an  opacity  in  the  pupil- 
lary area,  the  periphery  remaining  clear.  Others  see  better  in  a 
bright  light  with  a  contracted  pupil ;  these  are  cases  with  an  opacity 
extending  toward  the  pole,  but  leaving  the  pupillary  area  clear. 

Opacities  at  the  pole,  or  on  the  axis  between  the  two  poles,  may 
escape  the  patient's  notice  if  they  are  small,  dense,  and  sharply  de- 
fined, but  they  may  be  a  great  detriment  to  vision  if  they  include 
the  entire  pupillary  area  in  the  form  of  a  translucent  veil  {see  p. 
2j^,  the  optical  effect  of  corneal  opacities).  Even  a  completely 
opaque  lens  does  not  destroy  vision.  Although  the  largest  part 
of  the  entering  light  is  absorbed  by  the  lens  or  reflected  from  it, 
yet  some  rays  may  pierce  the  lens  by  the  same  path  they  would 
all  take  under  normal  conditions.  It  is  therefore  possible  for  the 
eye  with  a  cataract,  even  if  it  involves  the  whole  lens,  to  recognize 
the  direction  from  which  luminous  rays  proceed,  and  to  indicate 
correctly  their  origin.  We  may  consequently  estimate  the  visual 
field  and  any  defects  in  it,  in  spite  of  an  opaque  lens.  Obviously, 
the  disk  for  testing  must  be  some  luminous  object,  like  a  candle 
flame.  As  a  rule,  it  is  sufficient  to  use  the  ophthalmoscope  for  the 
purpose  of  throwing  light  into  the  eye  from  various  directions  and 
to  ask  the  patient  to  tell  where  it  comes  from.  If  a  correct  answer 
is  quickly  given,  it  is  assumed  that  retina  and  optic  nerve  are 
healthy.  To  be  absolutely  sure,  the  patient's  light-sense  must  be 
tested.  An  eye  with  a  totally  opaque  lens  ought  to  be  as  sensitive 
to  light  as  a  healthy  eye  with  the  lids  closed.  A  patient  with  cata- 
ract should  recognize  in  a  dark  room  an  ordinary  candle  flame  at 
6  in.,  and  a  very  small  lamp  (that  is,  a  lamp  with  its  wick  turned  so 
low  that  the  flame  is  only  a  blue  color)  at  o.j  in.  The  play  of  the 
pupil  must  also  be  noticed;  with  a  normal  light  perception  the  eye 
having  a  cataract  should  contract  distinctly  if  light  is  suddenly 
thrown  into  it. 

Even  colors  may  be  recognized  in  spite  of  total  opacity  of  the 
lens,  but  the  patient  may  make  certain  mistakes  in  naming  them  if 
the  nucleus  is  sclerotic  and  therefore  yellow  or  brownish-red  ;  only 
such  mistakes,  however,  as  a  healthy  person  would  make  if  he 
should  look  through  yellow  or  brownish-red  glass. 

Other  signs  for  the  diagnosis  of  the  conditions  found  within  the 
eye  itself  are  supplied  by  the  ophthalmoscopic  examination  of  the 
other  eye,  assuming,  of  course,  that  its  fundus  is  visible. 


CATARACTA    SENILIS.  335 

Objective  evidence  of  an  opacity  in  the  lens  is  at  times  given  by 
merely  looking  at  the  eye.  If,  for  example,  the  vicinity  of  the 
anterior  pole  is  cloudy,  the  pupil  appears  grayish-white  instead  of 
the  normal  black.  It  must  not  be  supposed,  however,  that  every 
grayish  discoloration  in  the  pupil  is  caused  by  cloudiness  of  the 
lens  ;  it  merely  indicates  that  light  is  diffusely  reflected  back  from 
the  lens,  the  amount  being,  perhaps,  only  the  minutest  portion  of 
all  the  entering  light,  while  the  largest  portion  passes  unhindered 
to  the  retina.  Pupils  of  old  persons  seldom  appear  quite  black, 
but  usually,  especially  if  they  are  dilated,  the  color  is  gray  or  a 
grayish-yellow,  the  sclerotic  lens  nucleus  reflecting  some  diffused 
light  back  again.  IVf  m'c  justified  in  assiiviing  an  opacity  only  ivhen 
a  distinct  area  in  the  lens  appears  gray  or  white  to  light  throivn  onto 
it,  and  black  to  light  throivn  through  it.  The  examination  for  the 
former  appearance  is  made  by  focal  illumination  (/.  g8^\  for  the 
latter  appearance  by  the  ophthalmoscope  (/.  US'). 

To  bring  the  whole  lens  completely  under  observation  it  is 
necessary  to  dilate  the  pupil  with  cocain  or  homatropin,  although 
even  with  their  aid  the  extreme  edge  may  still  be  invisible.  In 
eyes  on  which  there  has  been  performed  an  iridectomy  extend- 
ing to  the  periphery,  the  edge  of  the  lens  is  perceptible,  as  a  rule 
looking  like  a  golden  ring  under  focal  illumination,  and  like 
a  broad,  dark  band  under  transillumination  with  the  ophthalmo- 
scope. 

Cataract  is  seen  at  all  ages, but  by  far  the  most  frequently  in  old 
persons,  next  in  young  infants,  and  most  rarely  in  the  prime  of  life. 
The  probability  of  the  development  of  cataract  increases  rapidly 
from  the  fiftieth  year  on,  and  reaches  its  maximum  at  the  eightieth 
year, 

2.  DIFFERENT  FORMS  OF    CATARACT. 

{a)  Cataracta  Senilis. — Senile  cataract  develops  usually  between 
the  fiftieth  and  seventieth  year  of  life,  that  is,  in  lenses  having  a 
nucleus  already  sclerotic.  A  hard,  unclouded  and  transparent  nucleus, 
and  a  soft,  but  clo2tded  and  therefore  untransparcnt  cortex  are  char- 
acteristic of  senile  cataract.  It  attacks  both  eyes,  seldom  at  the  same 
time,  however.  There  are  often  early  symptoms  preceding  a  cata- 
ract, such  as  multiple  vision  in  one  eye  (^polyopia  monocularis^. 
This  depends  upon  the  division  of  the  cortex  into  sectors,  and  since 
these  sectors  do  not  lie  exactly  symmetrical  to  the  axis  of  vision, 
each  sector  projects  its  own  image  of  the  object  looked  at,  and  these 


336  DISEASES    OF   THE    LENS. 

different  images  do  not  coincide.  Another  early  symptom  is  short- 
sightedness, not  an  apparent  condition  depending  on  reduced  visual 
acuity,  but  an  actual  condition  due  to  a  real  approach  of  the  far 
point  toward  the  eye.  This  may  be  due  to  a  change  of  the  refrac- 
tive index,  or  to  an  expansion  of  the  lens  with  the  accompanying 
advance  of  the  anterior  lens  surface. 

If  myopia  were  caused  by  a  thickening  of  the  lens  nucleus  it  would  certainly  result  in 
every  aging  eye.  It  is  well  known  that  such  is  not  the  case.  On  the  contrary,  many 
aging  eyes  lose  in  refractive  ^owtr  [pp.  ^8  and  ^5).  This  maybe  explained  thus: 
Thickening  of  the  nucleus  raises  its  refractive  index,  and  consequently  the  refractive 
power  of  the  eye ;  but  while  the  nucleus  is  thickening  it  is  at  the  same  time  flattening 
and  thereby  losing  its  converging  strength.  If  thickening  and  flattening  maintain  an 
equilibrium,  there  is  no  change.     If  the  thickening  predominates,  myopia  is  the  result. 

Whether  with  or  without  the  preceding  segmentation  in  the 
lens,  wedge-shaped  opacities  are  formed,  each  with  apex  toward  the 


Fig.  121. — Beginning  Cataract,  unuek  Transillumination,  with  Dilated  Pupil. 
{After  Jaeger.) 

pole  and  base  toward  the  equator  {Fig.  121) ;  the  narrower  the 
wedge  the  slower  is  the  progress  of  the  cataract.  These  spoke- 
like opacities  are  soon  accompanied  by  lines,  dots,  and  clouds. 

As  Foerster  shows,  the  first  spokes  are  only  fissures  or  cleavages 
filled  with  fluid  of  a  refractive  index  different  from  that  of  its  sur- 
rounding. This  fluid  coagulates  into  "  Morgagni's  drops."  As 
cataract  develops  the  lens-fibers  degenerate,  as  may  be  recognized 
microscopically  by  fine  punctate  molecular  opacities.  The  points 
coalesce  to  drops,  and  the  fibers  are  stretched  till  they  finally  burst. 
These  points  look  like  fat-drops,  and  are  held  to  be  myelin ;  they 
can  be  recognized  even  after  the  rupture  of  the  lens-fibers  by  their 
possessing  a  higher  refractive  index  than  that  of  the  surrounding 
fluid.  Close  to  them  are  seen  also  cells  of  swollen  epithelium  vary- 
ing in  shape,  and  of  appreciable  size. 


CATARACTA    SENILIS.  337 

In  proportion  as  the  opacities  increase  in  number  and  size  and 
encroach  upon  the  pupillary  area  the  visual  acuity  declines.  The 
patient,  who  is  probably  presbyopic  and  has  worn  reading  glasses 
for  years,  usually  complains  that  his  glasses  "  don't  fit,"  or  he  says 
there  are  black  spots  in  front  of  his  eye,  which  means  that  when  he 
moves  his  eye  the  retina  perceives  the  flitting  of  the  shadows 
which  the  opacities  throw  on  it.  The  physician  makes  a  diagnosis 
of  beginning  cataract  {cataracta  incipiens),  and  has  now  to  choose 
whether  he  shall  tell  the  patient  or  keep  silent.  It  is  best  to  let  the 
decision  rest  upon  his  estimate  of  the  time  that  will  elapse  before 
an  operation  will  become  necessary.  This  may  often,  but  not 
always,  be  estimated  by  the  condition  of  the  cataract.  Small  spokes 
of  grayish -yellow  color  indicate  a  slow  course,  while  broad,  bluish- 
white  spokes  of  a  silken  luster  are  more  probably  of  a  rapid  course. 
If  the  patient  is  old  the  cataract  probably  grows  slower.  In  very 
old  persons  an  opacity  may  never  reach  maturity.  If  the  appear- 
ance of  the  cataract  is  not  indicative  of  its  rate  of  growth,  it  is  a 
good  plan  to  draw  for  record  the  size  and  position  of  the  more 
prominent  opacities,  and  to  measure  the  visual  acuity,  and  to  com- 
pare these  with  the  conditions  when  the  patient  presents  himself 
two  or  three  months  later.  If  the  visual  acuity  is  reduced  and  if 
the  opacities  are  increased,  a  rapid  course  may  be  assumed.  If 
progress  is  slow,  conditions  may  not  materially  change  for  months 
or  years. 

As  the  opacities  increase  and  as  the  visual  acuity  diminishes 
correspondingly,  the  lens  swells.  This  is  recognized  by  the  fact 
that  the  anterior  chamber  grows  shallower.  This  swelling  of  the 
lens  depends  upon  an  absorption  of  water  by  the  lens  cortex.  The 
cataract  in  this  stage  is  called  cataracta  iminatiira  jfiaturesccns,  or 
nondum  matura,  not  yet  ripe  for  extraction.  The  iris-shadow  test, 
used  to  demonstrate  that  the  lens  cortex  is  not  yet  fully  opaque,  is 
performed  as  follows:  The  eye  is  illuminated  from  one  side  by  a 
convex  lens,  while  the  physician  looks  into  the  eye  from  the  other 
side ;  if  the  lens  is  completely  opaque,  it  is  seen  that  the  white 
reflected  from  it  and  the  dark  brown  of  the  pigment  layer  at  the 
edge  of  the  iris  lie  immediately  against  each  other.  If,  on  the 
contrary,  the  external  cortical  layer  of  the  lens  is  still  unclouded 
and  therefore  does  not  reflect  light,  there  will  be  seen  between  the 
white  of  the  pupil  and  the  pigmented  edge  of  the  iris  a  dark  inter- 
space or  ring:  an  expression  of  the  fact  that  the  iris  and  that  part 
22 


338  DISEASES    OF    THE    LENS. 

of  the  lens  which  reflects  h'ght  do  not  as  yet  He  in  immediate  con- 
tact. 

After  a  longer  or  shorter  time  the  stage  of  ripeness  is  reached, 
cataracta  tnatura.  The  cortex  is  now  fully  opaque,  the  swelling 
has  disappeared,  and  the  anterior  chamber  is  again  of  normal  depth  ; 
the  iris  throws  no  shadow  on  the  lens.  Visual  acuity  is  reduced  to 
counting  fingers  or  to  the  mere  recognition  of  the  movements  of 
the  hand  ;  a  candle  is  recognized  by  the  eye,  if  otherwise  normal, 
at  6  to  10  meters.  The  thicker  the  opacity,  which  means  the 
younger  the  patient,  the  worse  will  vision  be. 

If  the  cataract  is  not  operated  on,  it  changes  gradually  into  an 
overripe  condition,  cataracta  liypermatura.  This  overripeness  finds 
expression  in  a  decrease  in  size  of  the  lens,  in  consequence  of  which 
the  anterior  chamber  grows  deeper  than  normal  and  the  iris  trem- 
bles. It  may  also  be  noticed  that  the  spoke-like  opacities  are 
crossed  and  connected  together  by  encircling  bands. 

The  character  of  overripe  lens  substance  is  varying  : — 

(a)  Either  the  contents  of  the  capsule  is  poor  in  water  and  hard, 
"like  dried  glue,"  cataracta  dura  liypermatura.  This  character  of 
the  capsular  contents  acts  as  an  irritant  on  the  epithelium  of  the 
anterior  capsule,  so  that  an  inflammatory  growth  is  set  up  which 
leads  to  capsular  cataract,  not  a  happy  designation,  for  the  capsule 
itself  does  not  become  opaque,  but  rather  the  new  tissue  formed 
from  the  epithelium  and  deposited  within  the  capsule.  Capsular 
cataract  looks  chalky,  is  not  translucent,  shows  no  spokes  or  bands 
but  a  uniform  distribution  toward  the  surface,  and  lies — an  impor- 
tant factor,  too — in  the  pupillary  plane.  For  this  reason  it  might 
be  mistaken  for  deposits  on  the  anterior  capsule;  to  avoid  such  an 
error,  it  is  best  to  remark  that  deposits,  according  to  their  origin,  are 
connected  with  the  pupillary  edge  of  the  iris  and  appear  grayish- 
white,  neither  of  which  conditions  is  the  case  in  capsular  cataract. 

(/?)  Or,  the  overripeness  leads  to  fluidity  of  the  cortex.  The 
spokes  and  bands  disappear,  the  cortex  changes  to  a  homogeneous 
grayish-yellow  mush  in  which  floats  a  brownish  nucleus  that  shows 
its  edge  when  the  head  is  turned  in  certain  directions.  This  con- 
dition is  called  cataracta  morgagiiiana.  Here  also  the  anterior 
chamber  is  deeper,  the  iris  trembles,  and  capsular  cataract  is  devel- 
oped. Vision,  owing  to  definite  optical  principles,  is  in  cataracta 
dura  liypermatura  better,  and  in  cataracta  morgagniana  worse  than 
in  cataracta  matura  senilis. 


CATAKACTA    JUVENILIS CATARACTA   TRAUMATICA. 


339 


{b)  Cataracta  Juvenilis  {Phakomalacia,  Soft  Cataract  of  Young 
Persons). 

The  young  are,  to  be  sure,  although  much  less  frequently  than  the  old,  subject  to  cata- 
ract, but  since  their  lenses  have  not  as  yet  a  hard  nucleus,  the  development  of  cataract 
takes  a  somewhat  different  course.  In  senile  cataract  the  nucleus  remains,  as  a  rule, 
unchanged,  and  appears  about  the  same  as  any  nucleus  in  a  healthy  lens  of  the  same  age, 
but  in  juvenile  cataract  the  nucleus  goes  through  the  above-mentioned  stages  of  splitting, 
degeneration  of  fibers,  liquefaction,  and  perhaps  absorption.  In  juvenile  cataract  the 
appearance  of  the  first  opacities  is  not  noticed  at  the  equator,  but  rather  can  any  part  of 
the  lens,  even  the  nucleus,  be  strewn  with  punctate  opacities.  In  certain  cases  the  pos- 
terior pole  is  the  point  of  origin,  and  from  there  an  opacity  may  spread  to  the  posterior 
edge  (posterior  cortical  cataract.  Fig.  122)  till  it  finally  destroys  the  transparency  of  the 
whole  lens. 

The  results  of  juvenile  cataract  are  atrophy,  fluidity,  or  calcification.  In  an  atrophic 
soft  cataract  there  is  found  within  the  capsule  a  thick  mush  consisting  of  myelin,  fat, 
cholesterin,  lime,  and  detritus.  In  a  fluid  cataract  the  same  constituents  are  found  floating 
in  water ;   the  lime  kernels  may  so  predominate  that  the  contents   of  the  capsule   looks 


Fig.  122. — Central  Posterior  Cortical  Cataract. 
The  spokes  with  points  toward  the  middle  are  partly  at  the  anterior,  partly  at  the  posterior  edge. 

{After  Jaeger.) 


like  milk,  cataracta  lactea.  In  a  calcified  cataract  the  whole  lens  is  changed  to  a  thick, 
lumpy  mass,  cataracta  calcarea  or  gypsea. 

In  a  few  cases  the  contents  of  the  capsule  of  an  atrophied  or  fluid  cataract  is  absorbed. 
There  remains  then  only  the  capsule  itself,  cataracta  fiiemhranacea,  with  its  growth  of 
epithelium  (capsule  cataract)  and  the  debris  of  the  cataract  milk.  Individual  areas  of 
such  a  membranous  cataract  may  become  again  so  translucent  that  the  blind  eye  regains 
part  of  its  visual  strength. 

The  diagnosis  of  juvenile  cataract  must  be  made  by  its  general  appearance.  Broad 
spokes,  deep  clefts,  and  a  bluish-white  color  prove  that  there  is  much  soft  cortex  present. 
Moreover,  the  youthTulness  of  the  patient  shows  that  a  hard  nucleus  cannot  as  yet  have 
developed.      This  form  of  cataract  may  be  congenital  in  all  stages  of  its  growth. 

{c)  Cataracta  Traumatica. — If  the  anterior  lens  capsule  is  in- 
jured and  if  as  a  result  the  lens  fibers  come  into  contact  with  the 
aqueous  humor,  they  become  cloudy  and  swollen.  The  swollen 
matter  crowds  through  the  capsule  wound  into  the  anterior  cham- 


340  DISEASES    OF   THE    LENS. 

ber  and  is  gradually  dissolved.  If  the  capsule  wound  is  small  or 
blocked  by  the  overlying  iris,  the  process  may  stop  here,  the  wound 
healing  quickly  and  the  rest  of  the  lens  remaining  uninjured,  leav- 
ing a  capsule  cicatrix  as  memento  of  the  accident.  But  if  the  wound 
was  larger,  the  whole  lens  becomes  cloudy,  new  flakes  of  lens  mat- 
ter pass  into  the  anterior  chamber  and  are  dissolved,  the  process 
being  repeated  till  the  entire  contents  of  the  capsule  has  disap- 
peared. 

Accidental  capsular  injuries  have  shown  surgeons  one  way  of 
disposing  of  the  cloudy  contents  of  the  lens  capsule,  but  an  incision 
through  the  capsule  (Discission,  p.  j^6)  is  not  free  from  danger. 
The  epithelium  of  the  anterior  part  of  the  capsule,  if  brought  into 
contact  with  the  aqueous,  may  grow  so  luxuriously  as  to  produce 
a  secondary  cataract — cataracta  secimdaria  {p.JS4) — which  consists 
of  new-formed  tissue  and  insoluble  capsule.  If  the  capsule  wound 
is  large,  the  swelling  of  the  lens  matter  may  be  so  angry  as  to 
cause  iritis  and  secondary  glaucoma  {q.  v.). 

The  age  of  the  patient  plays  an  important  part  in  the  danger  of 
a  traumatic  cataract.  The  younger  the  patient,  the  quicker  does  the 
opacity  and  absorption  follow,  and  the  less  inclination  is  there  to 
inflammation  and  increased  tension.  Complete  absorption  cannot 
be  expected  if  the  nucleus  becomes  sclerotic.  The  older  the 
patient,  the  slower  does  clouding  advance,  and  the  greater  is  the 
danger  of  inflammation  and  increased  tension. 

In  injuries  to  the  lens  it  not  infrequently  happens  that  a  portion 
of  the  lens  already  opaque  becomes  again  transparent — as,  for 
example,  in  injuries  from  foreign  bodies.  Suppose  a  splinter  of  iron 
to  have  passed  through  the  entire  lens;  the  path  pursued  by  the 
foreign  body  becomes  opaque,  and  this  opacity  extends  over  a 
larger  portion  of  the  posterior  cortex  {Fig.  122).  Meanwhile  the 
anterior  and  posterior  capsule  wounds  close  up,  the  foreign  body 
having  been  removed.  Some  weeks  later  the  posterior  cortex  may 
be  found  transparent,  and  the  opacity  is  restricted  to  the  path  of 
the  bit  of  iron. 

If  a  very  small  and  aseptic  foreign  body  enters  the  eye  and 
remains  in  the  lens,  a  cataract  may  result  so  gradually  that  the 
patient  forgets  the  injury  before  his  increasing  visual  disturbance 
leads  him  to  the  surgeon.  Cases  have  been  reported  where  a  for- 
eign body  long  since  forgotten  has  been  found  in  a  lens  extracted 
for  what  was  supposed  to  be  senile  cataract. 


CATARACTA    STATIONARIA.  34 1 

Cataract  can  arise  from  a  severe  concussion  to  the  lens  without 
an  actual  capsular  wound  (see  Causes, /.  j^j). 

((/)  Cataracta  Stationaria. — One  factor  is  common  to  all  forms  of  cataract  yet  dis- 
cussed, namely,  that  the  disease  finally  makes  the  whole  lens  (or  rather  the  whole  cortex) 
opaque,  even  if  after  years  or  decades.  There  is  another  class  in  which  the  condition  is 
not  that  of  a  gradually  progressive  opacity,  but  of  a  fixed  and  completed  opacity  remain- 
ing unchanged  the  whole  life  long.  Examples  are  furnished  by  small  capsular  injuries. 
Another  example  is  that  mentioned  on  /.  22^  under  diseases  of  the  cornea,  as  anterior 
central  capsular  cataract,  consisting  of  a  small,  roundish,  glittering,  white  opacity  at  the 
anterior  pole  of  the  lens.  Such  an  opacity  protrudes  at  times  into  the  anterior  chamber, 
and  is  there  called  cataracta  pyramidalis.  It  must  not  be  supposed  that  the  opaque  mass 
is  outside  of  the  capsule.  The  opposite  is  the  case.  All  investigators  are  unanimous  in 
saying  that  the  "pyramid"  is  covered  by  the  uninjured  capsule,  lacking  its  epithelium, 
however ;  and  the  capsule,  where  it  passes  from  the  normal  surface  onto  the  pyramid,  is 
thrown  into  delicate  folds.  The  opaque  mass  consists  of  spindle-formed  cells,  the  off- 
spring of  the  missing  epithelium.  Anterior  central  capsular  cataract  may  be  congenital, 
due  probably  to  some  intrauterine  corneal  inflammation.  The  disturbance  to  vision 
depends  essentially  on  the  size  of  the  cataract  and  on  the  folds  in  the  capsule.  Becker 
and  others  have  seen  cases  with  normal  visual  acuity. 

A  form  of  cataract  quite  similar  in  appearance  is  found  at  the  posterior  lens  pole,  and 
is  called  posterior  polar  cataract,  cataracta  polaris  posterior.  This,  too,  is  characterized 
by  a  glistening,  white,  round  opacity.  With  focal  illumination  it  is  seen  to  be  like  a  con- 
cave mirror  with  the  concavity  directed  forward.  It  must  not  be  confused  with  posterior 
cortical  cataract  {Fig.  122) ,  which  has  a  quite  different,  radiating  shape,  a  yellow  color, 
and  is  by  no  means  stationary.  Anatomical  investigations  have  shown  that  posterior 
polar  cataract  is  not  a  genuine  lens  opacity,  but  a  deposit  on  the  posterior  capsule  anal- 
ogous to  the  iritic  deposit  ( />.  274)  at  the  anterior  pole.  This  posterior  polar  cataract  is 
the  result  of  some  disease  of  the  fetal  arteria  centralis  corporis  vitrei. 

There  is  still  another  form  of  congenital  nuclear  cataract,  cataracta  centralis.  It  is 
recognized  as  a  white,  circular,  sharply  outlined  opacity  in  the  depth  of  the  pupil.  Vision 
may  be  very  good,  as  the  patient  looks  through  the  side  of  the  opaque  nucleus  which,  by 
the  denseness  of  the  opacity,  acts  rather  to  diminish  light  instead  of  cutting  it  ofT  alto- 
gether. 

The  commonest  form  of  stationary  cataract  is  the  lamellar  or 
zonular  cataract.  It  appears  as  a  delicate  gray,  completely  homo- 
geneous opacity.  With  a  dilated  pupil  one  sees  that  the  sharply 
defined  circular  opacity  is  surrounded  by  a  more  or  less  broad, 
deep  black  edge.  By  focal  illumination  it  may  be  seen  that  the 
lens  cortex  is  clear;  the  cone  of  rays  entering  the  eye  undergoes 
reflection  at  the  anterior  capsule  on  the  one  hand,  and  at  the  opaque 
anteriorly  convex  lamella  on  the  other;  the  distance  apart  of  these 
two  reflexes  indicates  the  distance  of  the  lens  surface  from  the  clouded 
lamella.  In  case  the  opacity  is  so  very  delicate  that  it  can  be  trans- 
illuminated,  the  cloudiness  of  the  layer  lying  behind  the  nucleus, 
with  the  opaque  zone  anteriorly  concave,  may  be  demonstrated. 


342 


DISEASES    OF   THE    LENS. 


The  ophthalmoscope  provides  a  further  means  of  diagnosis.  If 
light  is  thrown  by  it  directly  into  the  pupil,  the  sharply  defined, 
circular  opacity  appears  dark,  not,  however,  uniform,  as  under 
oblique  illumination,  but  brownish-red  in  the  middle;^  the  equa- 
torial zone,  black  by  oblique  light,  now  appears  red. 

From  this  we  conclude  that  nucleus  and  cortex  are  transparent, 
and  that  the  opacity  is  restricted  to  a  zone  (lamella)  lying  between 
nucleus  and  cortex. 

The  results  of  dinical  investigation  are  confinned  by  the  anatomical  examinations 
(see  Fig.  /2j).     Deutschmann,  in  one  case,  found  the  nucleus  clear,  but  closely  sur- 
rounded by  a  thin  layer  of  opaque  cortex.      This 
ofiacity  was  due  to  the  fact  that  the  fissures  and  gaps 
between  the  lens-fibers  were  filled  with  fine-grained 
detritus   and   myelin   drops ;    the   fibers  themselves 
were  uninjured,  but  saturated  by  "  vacuoles ' '  and 
myelin  drops.     Around  this  opacity  was  a  zone  of 
clear  cortex,  then  a  second  belt  of  ojjacity.  not  yet 
completely  closed.     Outside  of  all  was  the  rest  of 
the  cortical  substance,  still  perfectly  normal.     Further 
investigation  has  shown  that  the  vacuoles   may  be 
present  in  the  nucleus,  but  not  in  such  abundance  as 
to  make  it  opaque.     If  this  latter  happens,  however,  the  conditicHi  is  that  of  stationary 
nuclear  cataract  and  is  dosely  related  to  lamellar  cataract. 

The  cortex  is  not  clear  in  all  forms  of  lamellar  cataract,  but  there 
are  often  found,  particularly  in  the  region  of  the  equator,  dots  or 
spokes,  the  latter  of  a  fork-like  form,  with  one  tooth  reaching  to 
the  anterior,  the  other  to  the  posterior  part  of  the  cortex  ;  these 
are  called  saddle  opacities,  because  the  forks  seem  to  ride  upon  the 
edge  of  the  lamellar  cataract.  Schirmer  explains  them  as  fissures 
resulting  from  an  abnormally  strong  contraction  of  the  nucleus. 
The  presence  of  these  opacities  arouses  the  suspicion  that  a  lamellar 
cataract  has  ceased  to  be  stationary  and  that  a  total  lens  opacity  is 
to  be  expected.  The  thicker  the  dots  and  the  broader  the  spokes, 
the  quicker  is  the  advance  of  the  cataract  to  be  assumed. 


Fig.     123  —  Lamellar    Cataract 
(ScmCHTSTAR).     {After  DeuUcJt- 


^  The  phencHnenon  b  explained  by  v.  Graefe  as  follows  :  In  direct  transillumination 
the  middle  of  the  opacity  is  struck  by  perpendicular  luminous  rays,  while  the  edge  of  the 
t^Mcity  is  struck  only  by  oblique  rays.  Consequently,  at  the  edge  of  the  opacity  more 
light  is  reflected  and  thus  prevented  from  entering  the  interior  of  the  eye.  The  same  con- 
dition is  true  of  light  which  returns  from  the  fundus  and  makes  the  pupil  appear  led. 
This  brighter  center  distinguishes  lamellar  from  nuclear  cataract ;  the  latter  is  obviously 
least  transparent  in  the  middle  and  therefore  appears  by  transillumination  darkest  in  that 


CAUSES  OF  THE  FORMATION  OF  CATARACT.         343 

Lamellar  cataract  appears  nearly  always  in  both  eyes.  It  maybe 
congenital  or  developed  during  the  early  years  of  life.  As  a  rule, 
however,  it  is  not  recognized  till  later,  when  the  child  shows  its 
inability  to  keep  up  with  school  requirements.  An  examination 
made  at  this  time  reveals  a  decidedly  reduced  visual  acuitv  ( —  to  — 
according  to  Becker's  e.xperience),  a  noticeably  small  range  of 
accommodation,  and  moderate  myopia. 

EHminotioQ  in  nn^e  of  accommodation  maj  be  okserred  m  other  fcvtns,  in  senile 
cataract,  for  example,  when  the  acoomrxtoion  is  less  tlum  that  wladi  canrspaods  to  the 
age  of  the  patient.  The  reason  is  that  Ae  dkfwti  leas  loses  the  power  of  dunging  its 
shape. 

Shorts^htedness  is  said  to  depend  oocasiaaallj  on  spherical  aberratkm.  That  »,  if 
the  opaque  zone  is  so  small  that  the  paricitf  can  look  to  one  side  of  it.  Us  retina  recdres 
images  from  rays  which  enter  at  the  peripheral  ptarts  of  cornea  and  leas,  and  which  are, 
therefore,  owing  to  faulty  or  incomplete  aplanatic  conditions,  more  strongly  refracted  than 
central  rays  would  be.     Myopia  may  also,  of  conree,  depend  on  the  length  of  the  eyeball. 

3.  CAUSES  OF  THE  FORMATION  OF  CATARACT. 

It  is  reasonable  to  suppose  that  a  transparent  tissue  composed  of  cells  is  in  a  cooditian 
of  unstal^le  equilibrium,  and  will  lose  this  equilibrium  if  the  adjustment  of  the  cells  to 
each  other,  the  uniformity  of  its  contents,  or  its  chemical  components  experience  any 
change.  This  of  itself  corresponds  to  or  explains  a  phenomenon  of  daily  life,  that  a  lens 
opacity  may  be  noticed  after  cold  and  disappears  after  heat.  Obviously  this  is  a  coagu- 
lation of  c«tain  substances,  perhaps  composed  of  fat  ai>d  albumin. 

The  formation  of  secondary  cataract  after  injuries  to  the  capsule  needs  no  particular 
mention,  since  it  is  not  to  be  expected  that  the  proliferated  and  changed  epithelial  cells 
will  produce  a  transf>arent  tissue.  But  opacities  result  from  injuries  that  hare  caused  no 
real  wound  to  the  capsule.  The  explanation  for  these  is  not  so  obvious.  It  most  be 
assumed  that  the  lens  is  not  shut  off  from  its  smionndings  by  the  capsule  in  an  absolutely 
watertight  compartment,  \mX  that  an  exchange  of  fluid  takes  place  between  the  lens  00 
the  one  side,  and  the  anterior  chamber,  the  vitreous  and  the  sjjaces  of  the  zonula  of  Zinn 
on  the  other.  But  the  great  thickness  of  the  antericH-  capsule,  and  farticularly  the  epi- 
thelium here  present,  prevent  this  exchange  of  fluid  from  being  too  active ;  at  the  back 
of  the  lens  this  danger  is  lessened  by  the  semifluid  character  of  the  vitreous.  If  now  any 
injury  tears  the  lens  free  from  its  normal  connection,  or  if  any  part  of  the  protective  epi- 
thelium dies,  the  normal  exchange  of  fluid  ceases,  nutrition  isdistmbed.  and  an  opacity 
rcsnlts.  For  instance,  a  dislocated  lens  r^Tilarly  becomes  opnqne,  and  even  an  incom- 
plete laceration  of  the  suspensory  ligament  may  produce  cataract.  Cataract  resulting  from 
a  lightning  stroke  may  be  used  as  an  example  of  opacity  due  to  the  destruction  of  epithe- 
lial cells. 

If  the  above  view  concerning  the  relation  of  the  lens  to  its  surroundings  is  correct, 
any  qualitative  change  in  aqueous,  vitrBons,  and  zonula  may  endanger  the  lens.  This  is 
actually  the  case.     We  know  that  lens  opacities  result 

(1)  From  chemical  alterations  in  the  flad  constihienfts  of  die  bodj  m  general,  and 

(2)  From  diseases  of  the  uveal  tract. 

Examples  under  ( I  \  are  furnished  by  the  cataracts  from  salt,  naphthalin,  and  si^ar. 
A  salt  cataract  can  be  produced  in  frogs  by  injecting  dihxrid  of  sodium  or  any  othernpidly 


344  DISEASES    OF    THE    LENS. 

diffusible  salt  beneath  the  skin.  Small  quantities  of  this  salt  reach  the  lens  and  effect 
such  a  chemical  union  with  the  materials  present  as  to  destroy  the  transparency.  A'ap/i- 
thalin  cataract  can  be  produced  in  rabbits  by  feeding  them  with  naphthalin.  This  begins 
like  senile  cataract  in  man,  with  streaks  and  spokes  in  the  cortex  at  the  equator.  Sugar 
cataract  (cataracta  diabetica)  has  been  seen  in  man  as  the  result  of  diabetes.  It  is  sup- 
posed that  it  is  not  the  passage  of  sugar  into  the  lens,  but  the  presence  of  sugar  in  the 
vitreous,  aqueous,  and  zonula,  which  causes  the  opacity.  The  why  and  wherefore  is  still 
dark,  since  not  enough  sugar  has  been  found  in  the  aqueous  to  ascribe  the  lens  opacity  to 
a  reduction  in  the  normal  proportion  of  water. 

Examples  under  (2)  are  furnished  by  the  numerous  cases  of  cataract  which  appear  as 
a  pathological  result  of  an  acute  or  chronic  inflammation,  or  of  some  non-inflammatory 
disease  of  the  eye.  Among  them  may  be  mentioned  the  diseases  of  the  uvea — iritis,  iri- 
docyclitis, choroiditis — and  myopia,  the  result  being  explained  by  the  fact  that  the  inflam- 
matory products  are  deposited  in  the  vitreous,  in  the  anterior  and  posterior  chamber,  that 
is,  in  the  tissues' adjacent  to  the  lens.  Retinitis  pigmentosa,  detachment  of  the  retina,  and 
glaucoma  may  also  be  mentioned. 

The  preceding  explains  the  origin  of  many  forms  of  cataract,  but  the  very  commonest, 
senile  and  lamellar  cataract,  are  not  touched  upon.  Both  these  forms  occur,  as  a  rule,  in 
healthy  persons  and  in  otherwise  healthy  eyes.  With  reference  to  lamellar  cataract  clini- 
cal observation  has  suggested  a  reason  for  its  origin.  In  about  four-fifths  of  the  patients 
with  lamellar  cataract  a  persistent  rachitis  (rickets)  has  been  found,  especially  faulty 
development  of  the  dental  enamel,  or  malformations  of  the  skull,  or  nodules  at  the  joints 
of  hollow  bones,  or  the  "rachitic  rosary,"  or  perhaps  many  of  these  signs  together. 
Lamellar  cataract  is  therefore  assumed  to  be  a  rachitic  eye  disease,  and  we  suppose  that 
the  cortical  zone  developed  during  the  period  of  rachitis  became  cloudy  through  nutri- 
tive disturbances,  but  that  lamellae  deposited  after  the  rachitis  ceased  were  clear.  But 
why  the  lack  of  earthy  salts  in  the  tissues  of  the  body — and  that  is  the  essence  of  rickets 
— can  induce  the  formation  of  opaque  lens  fibers  is  of  itself  not  quite  plain. 

Senile  cataract  has  found  no  explanation  which  is  at  the  present  day  universally 
accepted.  We  know  only  that  age  predisposes  to  cataract.  We  do  not  know  why. 
We  might  assume  a  senile  atrophy  of  certain  parts  of  the  uvea  and  a  consequent  malnutri- 
tion of  the  lens.  We  might  assume  a  mechanical  explanation  ;  Becker  supposes  that 
with  the  sclerosis  of  the  nucleus  there  is  also  an  atrophy  which  the  equatorial  region  can- 
not follow  so  easily  as  the  polar  regions;  there  is  consequently  a  fissure  at  the  equator. 
Thus  the  formation  of  cataract  is  begun  by  a  cause  ascribed  to  disturbance  of  nutrition, 
at  one  time  little  understood.  There  is  also  no  light  thrown  on  the  matter  by  the  circum- 
stance that  cataract  is  hereditary  in  certain  families.  Schoen's  view,  that  senile  cataract 
is  the  result  of  undue  strain  on  the  accommodation,  is  so  far  more  opposed  than 
upheld.  Michel's  doctrine,  that  senile  cataract  is  due  to  some  such  cause  as  atheroma 
of  the  arteries,  has  made  no  greater  impression. 

4.  TREATMENT  OF  CATARACT. 
An  opacity  of  the  lens  once  formed  cannot  be  cleared  up.  This 
admits  of  very  few  exceptions,  one  such  being  mentioned  on /.j^o, 
while  diabetic  cataract  may  be  an  exception,  and  some  physicians 
claim  to  have  seen  opacities  disappear  after  treatment  at  Carlsbad. 
Indirectly  a  disappearance,  complete  or  incomplete,  may  be  effected 
by  absorption  (/.  Jjp).     (A  form  of  spontaneous  cure  results  from 


TREATMENT  OF  CATARACT.  345 

luxation  of  the  lens,  q.  t'.).  The  treatment  of  unripe  cataract  must 
therefore  be  restricted  to  the  prescription  of  proper  "  reading 
glasses,"  or  glasses  with  a  handle.  Occasionally  smoked  glasses 
are  serviceable  by  effecting  a  reduction  of  the  light  so  frequently 
complained  of,  or  by  a  dilatation  of  the  pupil  reflexly  (/.  Jjj). 
For  the  same  reason  atropin  may  be  of  service  for  a  period  of  time. 
The  general  health  of  the  patient  must  be  protected,  since  cataract 
may  make  rapid  advances  after  exhausting  diseases. 

The  essential  treatment  of  cataract  consists  in  removal  of  the 
opaque  lens,  and  is  therefore  operative. 

What  cataracts  can  be  operated  on  ?  Those  cases  must  be 
rejected  in  which  a  better  visual  acuity  cannot  be  obtained  by  rea- 
son of  some  other  disease  (of  the  retina,  choroid,  or  optic  ^^rve) 
existing  behind  the  lens.  The  presence  of  complications  can  at 
times  be  assumed  by  the  appearance  of  the  cataract ;  for  example, 
cataracta  calcarea  occurs  almost  always  in  eyes  already  totally 
blind.  Moreover,  many  a  complication  may  be  discovered  by 
examining  the  light  sensation  and  the  field  of  vision  {p.  334).  No 
operation  should  be  performed  on  a  stationary  cataract  in  which 
the  visual  acuity  suffices  for  the  patient's  vocation  or  may  be  made 
to  suffice  by  the  production  of  an  artificial  pupil.  Finally,  a  cata- 
ract operation  should  be  postponed  if  only  one  eye  is  affected,  the 
other  remaining  healthy,  since  the  advantage  of  an  increased  visual 
field  does  not  compensate  for  the  danger  that  always  threatens  the 
other  eye  during  an  operation  for  cataract.  Even  a  successful 
operation  cannot  add  other  advantages  than  this  just  mentioned, 
for  essential  binocular  vision  cannot  be  expected,  owing  to  the  great 
optical  disparity  between  the  eye  operated  on  and  the  unaffected 
eye.  If,  however,  the  second  eye  shows  a  beginning  cataract,  or 
for  any  other  reason  is  unserviceable,  the  first  must  be  operated 
on. 

If  an  operation  is  decided  on,  the  next  question  is  as  to  the  proper 
time  for  it.  Overripe  and  ripe  cataracts  can  be  attacked  at  once. 
Unripe  cataracts,  on  the  other  hand,  should  be  waited  for,  since  the 
chances  of  success  in  the  operation  on  unripe  cataracts  are  never 
so  good.  In  cases  where  maturity  is  approached  very  slowly,  or 
where  the  patient  for  any  reason  does  not  wish  to  wait,  Foerster's 
(Bettman's)  method  of  artificial  ripening  may  be  tried.  This  con- 
sists of  performing  an  iridectomy  or  of  releasing  the  aqueous  by  a 
corneal  puncture,  and  of  then  massaging  the  cornea  with  a  strabis- 


346  DISEASES    OF    THE    LENS. 

mus  hook  ;  the  lens  cortex  in  its  uninjured  capsule  is  thus  irritated 
and  the  opacity  makes  rapid  strides. 

Many  ophthalmic  surgeons  operate  on  unripe  cataracts  in  patients  of  sixty  years  and 
over.  In  such  old  people  an  easy  delivery  may  be  expected  even  if  the  lens  is  not  totally 
opaque,  especially  if  a  few  individual  opacities  are  to  be  seen  in  the  outer  cortical  layers. 
Landolt  declares  that  the  age  of  the  cataract  is  of  more  importance  in  this  respect  than 
the  age  of  the  patient  ;  the  longer  the  unripe  cataract  has  existed,  the  sooner  may  an  easy 
delivery  of  the  lens  be  expected. 

If  now  a  cataract  is  pronounced  to  be  ripe  or  at  least  operable,  it 
only  remains  to  choose  the  method  of  operation.  There  are  three 
at  our  disposal  : — 

(i)  The  lens  in  its  uninjured  capsule  maybe  pressed  downward, 
that  is,  pushed  out  of  the  pupillary  area  into  the  vitreous  by  means 
of  a  needle  entered  through  the  cornea  or  sclera — Depression  or 
Reclination  ; 

(2)  The  anterior  capsule  may  be  torn  by  a  cataract  needle,  and 
the  capsular  contents  left  to  be  gradually  absorbed — Discission  ; 

(3)  The  opaque  lens  may  be  removed  from  the  eye — 

{a)  By  drawing  it  out  through  a  hollow  needle — Suction, 
{b)  By  releasing  it  from  the  eye  by  an  incision — Extraction. 

The  first  method  may  be  passed  without  consideration.  For- 
merly it  was  universally  resorted  to,  but  is  nowadays  seldom  or  never 
applied,  since  not  only  may  an  eye  so  operated  on  go  blind  by  slow 
inflammation,  but  the  other  eye  may  also  be  destroyed  by  sympa- 
thetic ophthalmia.  The  method  is  admissible  in  atrophied  cataracts 
having  but  little  substance  and  no  power  of  swelling. 

Suction  is  worth  remark  only  for  the  fact  that  it  may  be  applica- 
ble in  a  fluid  cataract  without  nucleus.  The  choice  lies  really 
between  Discission  and  Extraction. 

Discission  is  applicable  in  soft  cataracts  without  hard  nuclei,  a 
condition  usually  the  rule  in  young  persons  up  to  the  twenty-fifth 
year.  Lamellar  cataract  is  therefore  almost  always  operated  on  by 
discission.  The  proceeding  is  as  follows :  The  pupil  must  be 
dilated  as  much  as  possible,  and  if  the  dilatation  is  only  moderate, 
it  is  better  to  give  up  discission.  The  necessary  instruments  are  ^ 
lid  speculum  {Fig.  g8,  p.  281),  fixation  forceps  {Fig.  yS,  p.  2ij)  and 
a  discission  needle  {Fig.  124).  The  needle  is  made  to  enter  to  the 
under  and  outer  side  of  the  center  of  the  cornea,  perpendicular  to  its 
surface.  After  the  needle  reaches  the  anterior  chamber  it  is  pushed 
on  till  its  point  touches  the  capsule  a  few  millimeters  beyond  the 


FLAP    EXTRACTION. 


347 


anterior  pole.  The  handle  is  now  raised  and  withdrawn  a  bit,  so  as 
to  cut  the  capsule  with  the  point  without  pressing  deep  into  the 
lens  or  touching  the  nucleus.  Then  the  needle  is  pulled  out  in  the 
same  path  it  was  pushed  in,  so  as  to  avoid  the  escape  of  the  aqueous 
as  much  as  possible.  A  deep  cut  into  the  lens  would  excite  too 
much  swelling,  a  danger  already  mentioned  {/>-JJp)-  The  escape 
of  aqueous  produces  a  contraction  of  the  pupil  and  the  accompany- 
ing danger  that  the  iris  may  be  brought  into  contact  with  the 
wound  in  the  capsule  and  adhere  to  it.  For  this  reason  the  pupil 
must  be  kept  dilated  with  atropin.  If  the  swelling  is  too  active, 
ice  compresses  may  be  used,  and  if  the  eyeball  shows  increased 
tension  in  spite  of  this,  the  swollen  mass  must  be  let  out  by  a  cor- 
neal incision  about  5  7/im.  long:  simple  linear  extraction.^  It  often 
happens  that  after  a  time  the  lens  substance  ceases 
to  be  absorbed,  either  because  the  capsule  wound 
has  closed,  or  because  the  aqueous  has  become 
saturated  with  the  substance  already  dissolved. 
In  the  latter  case  the  promise  of  success  may  be 
held  out  that  release  of  the  aqueous  by  a  corneal 
puncture  will  at  least  set  up  further  absorption. 
If  the  capsule  wound  is  closed  it  will  not  be 
opened  by  a  simple  release  of  aqueous,  and  the 
discission  must  therefore  be  repeated.  A  cure  of 
cataract  by  discission  requires  several  months. 

The  treatment  of  senile  cataract — cataract  with 
sclerotic    nucleus — is    summed    up    in    the   word 
Extraction.     There  are  two  methods:   Daviel's,  ox  flap  extraction, 
and  v.  Graefe's  peripheral  linear  extraction.     The  latter  implies  an 
iridectomy,  the  former  does  not. 

(a)  Flap  Extraction,  ^i-A'.i'. — Instruments:  Lid  speculum  (/v^.  gS,  p.  281),  fixa- 
tion forceps  {Fig.  j8,  p.  2ij),  v.  Graefe's  {Fig.  126)  or  Beer's  {Fig.  i2j)  cataract  knife, 
Daviel's  spoon  with  v.  Graefe's  cystotome  {Fig.  127).  The  patient  lies,  the  surgeon 
stands  at  his  head  if  the  right  eye  is  to  be  operated  on,  at  his  side  if  the  left  eye  is  to  be 
operated  on.  After  the  lid  speculum  is  adjusted,  the  surgeon  seizes  a  fold  of  the  con- 
junctiva and  enters  the  knife  at  a  {Fig.  128),  about  0.5  mm.  inside  the  corneal  margin, 
carrying  it  parallel  to  the  plane  of  the  iris  through  the  anterior  chamber;  at  b  the  knife 
is  brought  out  and  the  flap  completed  downward,  by  a  straight  cut  if  Beer's  knife  is  used, 
by  a  sawing  movement  if  the  instrument  is  v.  Graefe's.      The  red  line  shows  the  location 


Fig.  124. — Discission 
Needle. 


^  Simple  linear  extraction  is  applicable  to  totally  opaque  cataracts  of  young  persons.* 
But,  of  course,  the  capsule  must  be  opened  after  the  linear  incision,  and  this  may  be 
effected  by  the  lance  knife  (keratome). 


348 


DISEASES    OF    THE    LENS. 


of  the  flap.  The  surgeon  now  introduces  the  small  hook  turned  flat  and  with  the  back 
in  advance  into  the  anterior  chamber,  turns  the  point  toward  the  capsule  and  tears  it  open 
with  gentle  pressure  ;  a  second  incision  perpendicular  to  the  first  completes  the  opening 
in  the  capsule.  All  the  instruments  are  now  removed,  and  the  delivery  of  the  lens  is 
accomplished  by  the  surgeon,  who  lays  the  index  finger  of  one  hand  on  the  lower  lid 
and  the  thumb  of  the  other  hand  on  the  upper  lid,  and  with  gentle  jiressure  with  the 
latter  on  the'  upper  part  of  the  cornea  turns  the  lens  on  its  horizontal  axis  ;  the  lens  thus 
presents  its  lower  margin  in  the  wound,  and  by  moderate  pressure  on  the  upper  lid  it  is 
worked  out.  The  somewhat  prolapsed  iris  is  replaced  with  a  spatula  or  Daviel's  spoon, 
and  any  lens  fragments  are  removed  by  scooping  them  out  with  Daviel's  spoon. 


Fig.  125. — Beer's  Knifr. 


Fig.  126. — V.Gkaefe's  Kmff. 


Fig.  127.  —  Daviel's  Spoon, 
WITH  Sharp  Hook  for 
Teaking  the  Capsule. 


This  procedure  gradually  drove  from  the  field  the  method  of 
depression  that  had  alone  ruled  to  the  middle  of  the  eighteenth 
century.     Brilliant  results  were  obtained  by  it,  but  certainly  in  one- 


FiG.  128. — Daviel's  Flap  Incision. 


tenth  of  the  cases  there  was  suppuration  of  the  cornea,  or,  at  least, 
an  inflammation  in  the  eye  that  led  to  complete  and  hopeless  blind- 
ness. As  the  suppuration  was  explained  by  the  separation  of  the 
flap,  V.  Graefe  decided  to  avoid  a  corneal  flap  by  (/)  making  the  inci- 
sion in  the  sclera,  and  {2)  carrying  it  along  a  great  circle  of  the  sphere  ; 
but  since  in  such  a  cut  the  iris  prolapsed,  an  accompanying  excision 
of  the  iris  became  imperative.     To  prevent  the  aperture  in  the  iris 


V.    GRAEFE  S    PERIPHERAL    LINEAR    EXTRACTION. 


349 


from  admitting  too  much  light,  incision  and  iridectomy  were  made 
above,  where  the  upper  lid  could  cover  them.  The  result  justified 
expectation.  Suppuration  of  the  cornea  became  noticeably  less, 
while  the  failures  and  los.ses  were  reduced  one-half  On  the  other 
hand,  chronic  iritis  and  cyclitis  were  more  frequent  than  before,  and 
led  occasionally  to  .sympathetic  inflammation  of  the  other  eye. 

(/')  V.  Graefe's  Peripheral  Linear  Extraction. — Instruments  :  Lid  speculum, 
fixation  forceps,  v.  Graefe's  cataract  knife,  iris  forceps  and  scissors,  hook,  two  Daviel's 
spoons.  Weber's  scoop  [Fig.  i2g)  or  lens 

spoon  {Fig.  130).     The  surgeon  stands  li^ 

at  the  patient's  head   for  the  right  eye,  (     ^  \jj 

he  sits  or  stands  at  the  left  side  for  the 
left  eye.  For  the  first  step,  the  incision, 
the  knife  is  entered  at  a  {Fig.  iji) 
toward  the  center  of  the  anterior 
chamber,  in  order  to  make  the  wound 
on  the  inner  surface  of  the  sclera  as 
large  as  that  on  the  outer  surface. 
When  the  point  of  the  knife  has  reached 
the  center  of  the  pupil  it  is  directed 
toward  the  spot  of  exit,  b,  and  the  cut 
is  completed  by  a  sawing  motion.  If 
the  knife  were  held  parallel  to  the  plane 
of  the  iris,  it  would  cut  its  way  out  in 
the  red  dotted  line  ;  but  since  this  is  not 
the  intention,  the  knife  must,  during  the- 
cut,  be  turned  on  its  long  axis  so  as 
gradually  to  bring  the  edge  more  and 
more  forward  (or  upward).  When  the 
sclera    is    pierced,    the    blade    is    again 

turned  so  as  to  lie  parallel  to  the  conjunctiva,  in  which  position  the  conjunctiva  is 
separated  from  the  sclera ;  after  this  has  been  accomplished  for  the  distance  of  2  to  j 
mm.  the  blade  is  again  turned  forward  and  the  conjunctival  flap  completed.  This  serves 
to  effect  an  immediate  closure  of  the  scleral  wound. 


i! 

I 

t 

? 

^ 

g 

l/l 

^ 

Ill 

, 

Fig. 

129. — Webek's 

KiG.  130  —Lens  Spoon 

S 

COOI 

Fig.  131. — V.  Graefe's  Peripheral  Linear  Extraction. 


The  cut  is  not  absolutely  linear,  that  is,  it  does  not  coincide  with  a  great  circle  ;  it  is 
rather  an  incision  with  the  formation  of  a  very  small  flap  of  /.j  to  2  tnm.  breadth. 

The  second  step,  the  iridectomy,  is  now  made.  Occasionally  the  iris  is  floated  out 
by  the  aqueous  as  it  escapes  after  the  incision  is  completed.  The  iris  is  in  any  case 
seized  by  the  iris  forceps  {Fig.  8g),  pulled  from  the  wound,  and  cut  with  one  stroke  of  the 


350  DISEASES    OF    THE    LENS. 

scissors  curved  on  the  flat,  the  scissors  being  held  parallel  to  the  scleral  wound  and  pressed 
firmly  against  the  eyeball.  The  third  step,  cystotomy,  consists  in  opening  the  lens  capsule. 
For  this  purpose  a  capsule  hook  (^4'-  ^^7')  '^  introduced  into  the  wound  at  the  angle  to 
the  right  and  passed  obliquely  to  the  left  till  it  reaches  the  edge  of  the  iris,  and  is  then 
turned  to  bring  the  point  toward  the  capsule,  over  which  it  is  drawn  in  a  horizontal  direc- 
tion ;  the  \to\x\X.  of  the  hook  is  thus  made  to  cut  a  flap  in  the  anterior  capsule.  The  fourth 
step  is  the  delivery.  For  this  purpose  one  Daviel's  spoon  is  placed  at  the  upper  lip  of 
the  wound  parallel  to  it,  and  a  second  is  pressed  gently  against  the  lower  third  of  the 
cornea  until  the  greatest  diameter  of  the  lens  has  passed  beyond  the  wound.  Pressure 
is  then  stopped,  and  the  lens  is  pushed  out  from  below.  Any  remaining  fragments  of 
cortex  may  be  expelled  by  stroking  the  cornea  with  the  Daviel's  spoon.  Care  must  be 
now  taken  that  the  iris  is  not  engaged  in  the  wound  ;  if  it  is,  it  must  be  pushed  back  into 
the  anterior  chamber,  or  if  this  is  not  successful,  it  must  be  picked  up  again  in  the  iris 
forceps  and  cut  off.  If  vitreous  presents  in  the  wound  before  the  lens  is  delivered,  all 
instruments  that  might  cause  pressure  on  the  eyeball  must  be  removed,  and  the  lens 
extracted  by  the  wire  scoop  {Fig.  i2g)  or  by  the  spoon  (/>^.  130). 

In  the  last  twenty  years  we  have  learned  that  in  suppuration  of 
the  cornea,  it  is  not  bad  nutrition  of  the  flap  but  infection  which 
plays  the  principal  role  !  Since  at  the  present  day  we  can  with 
almost  absolute  certainty  prevent  infection,  the  dispute  over 
Daviel's  and  v.  Graefe's  operations  (long  ago  decided  in  favor  of 
v.  Graefe's)  has  broken  out  anew.  In  favor  of  Daviel's  operation 
is  the  retention  of  a  round  and  movable  pupil,  which  looks  better, 
causes  no  dazzling,  and  to  a  certain  extent  offsets  the  lack  of 
accommodation  by  the  fact  that  it  is  reflexly  contracted  when  near 
objects  are  gazed  at;  peripheral  vision  is  also  better  with  a  round 
and  contracted  pupil  than  with  an  iris  coloboma  ;  and  the  danger 
of  sympathetic  inflammation  in  the  other  eye  is  less  in  Daviel's 
operation.  On  the  other  hand,  the  danger  of  iris  prolapse  and  its 
attendant  evils  is  greater  in  Daviel's. 

Landolt  has  instituted  inquiries  among  ophthalmic  surgeons  of 
all  countries.  As  the  result  of  his  questions,  and  of  his  own  ex- 
perience, Landolt  has  formulated  the  rule  that  the  operation  with- 
out iridectomy  is  suitable  only  for  the  best  cases,  that  is,  for 
cataracts  in  which  a  smooth  and  complete  delivery  of  the  lens 
may  be  anticipated  in  patients  of  a  healthy,  calm,  and  intelligent 
disposition. 

I  have  myself  always  operated  with  an  iridectomy,  and  shall  for  the  present  stick  to 
it.  I  acknowledge  that"  complete  success"  with  Daviel's  method  is  of  more  value  to 
the  patient  than  the  same  visual  acuity  obtained  after  a  v.  Graefe's  operation,  but  that 
the  chances  are  less  to  attain  this  result  in  Daviel's  operation.  Moreover,  the  danger  of 
making  V.  Graefe's  incision  too  peripherally  is  essentially  reduced  hy  VAing  Jacobson  s 
incision  at  the  corneal  limbus.      (/"4''.  ^3--) 


TREATMENT — BEFORE  AND  AFTER.  35  I 

The  length  of  the  incision  depends  upon  the  size  of  the  nucleus. 
In  case  this  cannot  be  correctly  estimated  in  advance,  it  is  best  to 
allow  room  for  the  passage  of  a  very  large  nucleus,  say  from  7  to 
8  vim. 

The  ideal  of  a  cataract  operation  is  without  doubt  the  delivery 
of  the  lens  in  an  unruptured  capsule.  This  method  has  been  de- 
veloped and  recommended  by  the  Pagenstecher  brothers.  It  de- 
viates from  V.  Graefe's  extraction  only  in  this :  that  after  the  iri- 
dectomy is  completed  a  spoon  is  passed  behind  the  upper  edge  of 
the  lens,  and  by  gentle  pressure  on  the  lower  third  of  the  cornea 
the  lens  is  encouraged  to  come  out.  If  this  does  not  succeed,  the 
spoon  is  passed  still  deeper  in,  up  to  the  posterior  pole,  and  the 
lens  is  slipped  out  by  pressing  it  lightly  against  the  inner  surface 
of  the  cornea.  This  method  is  applicable  if  the  capsule  is  tough, 
the  Zonula  Zinnii  (suspensory  ligament)  weak,  and  if  there  is  any 
fluid  between  vitreous  and  lens.     Experience  teaches  that  in  over- 


FiG.  132. — Jacobson's  Incision. 

ripe  cataracts  the  capsule  is  tough  and  the  ligament  relaxed.  Loose- 
ness of  the  lens  in  the  saucer-shaped  depression  of  the  vitreous 
may  be  expected  in  cataracta  accreta  and  in  overripe  cataracts 
coupled  with  glaucoma.  The  few  cases  in  which  I  have  operated 
by  Pagenstecher's  method  have  been  among  my  most  successful 
ones. 

5.  TREATMENT— BEFORE  AND  AFTER. 

In  a  cataract  operation  the  greatest  danger  comes  from  infection. 
The  surgeon  must  therefore  exercise  all  his  skill  to  find  any  sources 
of  infection  and  to  counteract  them.  Particular  attention  must  be 
given  to  the  lacrimal  passages  and  the  nose,  the  conjunctiva  and 
lids.  Diseases  of  these  structures  must  be  treated  and  cured 
according  to  principles  already  given.  Unfortunately,  in  diseases 
of  the  lacrimal  apparatus  this  is  a  wearisome  task,  and  many 
surgeons  prefer  to  shut  off  the  tear  sac  from  the  conjunctiva,  either 
by  Eversbusch's  method  of  ligating  the  duct,  or  by  Haab's  method 


352  DISEASES    OF   THE    LENS. 

of  sealing  the  punctum  by  the  galvano-cautery ;  others  either  ex- 
pose the  sac  and  fill  the  space  with  iodoform  gauze,  or  extirpate  it. 
Chronic  conjunctival  catarrh  in  old  people  can  be  merely  bettered, 
not  cured.  In  such  cases  a  radical  disinfection  immediately  before 
the  operation  must  be  relied  on. 

The  general  health  of  the  patient  needs  attention  as  well.  We 
know  that  old,  and  particularly  poorly  nourished  persons,  are  prone 
to  hypostatic  congestion  of  the  lungs  during  continuous  rest  in 
bed.  We  know  also  that  the  closure  of  both  eyes  may  induce 
physical  disturbances,  alcoholics  being  noticeably  affected.  Many 
old  persons  suffer  from  chronic  bronchial  catarrh  and  cough,  or 
bladder  troubles,  all  being  conditions  in  which  rest  in  bed  is  an 
aggravation  or  an  impossibility.  In  such  cases  we  must  be  content 
with  a  shorter  or  less  constant  period  in  the  recumbent  position. 
To  alcoholics  it  is  best  to  give  a  modicurp  of  beer  or  wine.  Active 
catharsis  must  be  induced  in  all  cases  before  the  operation. 

The  immediate  preparation  of  the  patient  consists  of  a  good  soap 
and  water  bath  to  the  whole  body  including  the  head,  and  a  wet 
bandage  of  sublimate  over  the  eye  to  be  operated  on.  This  band- 
age is  to  be  removed  on  the  operating  table,  the  head  enveloped  in 
a  cloth  wet  in  sublimate  solution,  the  vicinity  of  the  eye  thoroughly 
washed  in  sublimate  i:iooo,  and  a  second  sublimate  cloth,  with  a 
hole  cut  in  it  for  the  eye,  is  to  be  spread  over  the  face.  The  eye 
is  now  cocainized  with  a  drop  oi  ?ifive  per  cent,  solution  applied  five 
times  at  intervals  of  one  minute  ;  the  entire  conjunctiva,  especially 
the  caruncles  and  the  adjacent  tissue,  is  to  be  wiped  off  with  cotton 
wet  in  sublimate  /  .•  looo,  followed  by  a  copious  douche  of  sublimate 
solution  /  .-5000.  The  operation  is  now  begun.  During  it  no  more 
sublimate  is  used  for  fear  of  provoking  corneal  opacities,  but  the 
eye  is  repeatedly  flushed  with  a  fresh  and  warm  three  per  cent,  boric 
acid  solution.  In  case  the  conjunctiva  or  lacrimal  passages  are  not 
absolutely  healthy,  the  wound  and  the  inner  canthus  of  the  eye 
are  powdered  with  sterile  iodoform.' 

It  is  assumed  that  the  cocain  solution,  the  dropper,  the  instru- 
ments, surgeon's  and  assistants'  hands  are  aseptic.  The  instru- 
ments are  taken  directly  from  2l  four  per  cent,  carbolic  acid  solution 

^  The  sterilization  of  the  iodoform  I  leave  to  the  druggist.  About  j.o  gm.  of  iodo- 
form are  placed  in  a  wide-mouthed  flask  with  about  lo.o  c.  c.  of  sterilized  water,  and 
boiled  on  a  water  bath  for  an  hour.  The  water  is  then  poured  out  of  the  flask  and  the 
moist  iodoform  dried  on  the  water  bath  in  the  same  flask  corked  with  cotton. 


TREATMENT — BEFORE  AND  AFTER.  353 

and  the  adherent  fluid  shaken  off.  The  bandage  consists  of  cotton 
dipped  in  /  .•  looo  sublimate,  and  gauze.  To  avoid  entropion  the 
under  lid  is  kept  in  place  by  a  sausage-shaped  roll  of  moist 
cotton. 

The  dreaded  suppuration  in  the  wound  may  be  avoided  with  cer- 
tainty by  following  these  precautions.  According  to  my  experi- 
ence, the  same  cannot  be  said  of  iritis  and  cyclitis.  These  condi- 
tions are  seen  in  cases  where  the  wound  was  closed  and  remained 
so  after  the  first  change  of  bandage,  the  wound  itself  not  being 
infected.  In  such  cases  we  must  assume  that  with  some  one  of 
the  instruments  germs  have  been  introduced  into  the  interior  of  the 
eye  without  finding  a  resting-place  at  the  scleral  wound.  It  must 
also  be  remembered  that  inflammation  may  be  produced  by  chemi- 
cal irritation,  or  by  the  swollen  lens  substance  not  yet  removed. 
An  iritis  or  a  cyclitis  may  even  result  mechanically  by  rupture  of 
an  adherent  remnant  of  capsule  or  iris. 

As  a  matter  of  routine  I  open  the  bandage  on  the  afternoon  of 
the  second  day,  that  is,  thirty  hours  after  the  operation,  because  a 
moderate  adhesive  iris  causes  no  particular  pain,  and  may  be  present 
with  no  complaint  from  the  patient.  If  I  find  the  bandage  dry,  the 
lid  edges  not  reddened,  no  photophobia  in  the  eye,  I  assume  that  no 
wound  infection  has  taken  place,  even  if  the  eye  itself  is  quite  red 
and  the  conjunctiva  somewhat  swollen  (chemotic) — this  last  might 
be  due  to  the  sublimate  alone.  Sterile  atropin  solution  is  now  dropped 
in,  and  a  bandage  reapplied.  The  same  treatment  is  continued  on  the 
next  day.  If  all  goes  smoothly  the  patient  may  sit  up  in  bed  the  third 
day,  and  stand  the  fifth  or  sixth.  The  healthy  eye  is  kept  band- 
aged with  the  eye  operated  on  for  about  five  days.  At  the  begin- 
ning of  the  second  week  the  bandage  may  also  be  omitted  from  the 
eye  operated  on.  Dark  glasses  should  be  used  for  protection 
against  strong  light,  and  the  ciliary  muscle  with  the  iris  must  be 
kept  at  rest  by  continuing  the  atropin.  After  two  or  three  weeks 
the  patient  may  be  dismissed  if  the  vicinity  of  the  cut  on  the  eye 
has  meanwhile  become  pale.  The  eye  is  not  to  be  used  yet.  Cata- 
ract glasses  with  permission  to  use  the  eye  must  not  be  given  till 
two  months  after  the  operation.  If  healing  does  not  take  place 
kindly — if  iritis,  cyclitis,  or  suppuration  in  the  wound  appears — the 
eye  must  be  treated  according  to  circumstances.  Energetic  atro- 
pinization  and  warm  compresses  with  boric  acid  solution  are  the 
principal  remedies  for  iritis  and  cyclitis  ;  disinfection,  or  if  neces- 


354  DISEASES    OF   THE    LENS. 

sary  the  cautery,  is  the  best  remedy  for  the  suppuration.  The 
striated  keratitis  (/.  2^2)  needs  no  particular  treatment. 

The  results  of  cataract  extraction  are  very  good.  In  preantisep- 
tic  days  the  loss  was  about  five  to  six  per  cent.  An  eye  was  called 
lost  which  could  not  count  fingers.  Thanks  to  antisepsis,  this  pro- 
portion has  noticeably  diminished,  at  the  hands  of  many  operators 
sinking  close  to  the  vanishing  point.  "  Unsuccessful  result  "  may 
be  entered,  if  the  patient  has  less  than  —  visual  acuity ;  "  success- 
ful result,"  if  more  than  — .  In  nearly  one-fourth  of  the  operations 
a  claim  is  made  for  V  =  i.' 

In  a  considerable  number  of  cases  the  visual  acuity  first  obtained 
will  gradually  decline.  This  depends  upon  the  development  of 
secondary  cataract. 

6.  CATARACTA  SECONDARIA. 
After  the  extraction  of  the  cataract,  the  fragments  of  the  anterior 
capsule  are  drawn  out  of  the  pupillary  area — if  everything  goes 
well — and  resting  on  the  posterior  capsule  they  finally  become 
adherent  to  it.  Capsular  epithelium  and  the  remnants  of  the 
cataract  are  therefore  removed  from  the  irritating  action  of  the 
aqueous.  The  nutritive  cells  at  the  lens  equator  do  hypertrophy, 
to  be  sure,  but  they  are  changed  into  normal  lens  fibers  as  far  as 
their  physical  characteristics,  if  not  their  form,  is  concerned.  The 
contents  of  the  intercapsular  space  consists  of  new-formed,  trans- 
parent lens  substance,  and  of  cataract  debris,  called  lenticular  mem- 
brane {Fig.  ijj).  Any  eye  operated  on  and  found  in  such  a 
condition  shows  a  black  pupil,  but  by  focal  illumination  there  is  seen 
behind  the  pupillary  plane  a  delicate,  striated,  silk-like,  often  trem- 
ulous membrane, — the  posterior  capsule.  Unfortunately,  this 
typical  condition  is  not  always  present.  The  fragments  of  the 
anterior  capsule  do  not  always  withdraw  from  the  pupillary  area, 
nor  adhere  early  to  the  posterior  capsule;  for  this  reason  the  debris 
of  the  cataract  swells  up  in  the  anterior  chamber,  the  epithelium  of 
the  capsule  continues  to  grow,  and  as  a  result  of  this  activity  there 
is  seen  in  the  pupillary  area  a  delicate  or  tough  gray  membrane, 
the  simple  secondary  cataract.     Visual  acuity  may  be  reduced  to 

^  It  has  seldom  been  my  experience  that  a  patient  can  read  line  No.  4  at  4 
meters  without  error;  but  we  may  record  V  =  —  if  one  or  several  of  the  letters  of  line 
No.  4  are  named  or  guessed  correctly. 


CATARACTA   SECONDARIA. 


355 


counting  fingers.  Even  this  is  not  the  worst  that  can  happen.  In 
many  cases  the  capsular  fragments  adhere  to  the  iris  or  to  the 
edges  of  the  wound,  a  condition  termed  cataracta  secmidaria  accreta. 
The  contraction  in  the  cicatrix,  the  movements  of  the  iris  and 
ciliary  muscle,  all  drag  continuously  on  the  secondary  cataract, 
which  gradually  increases  in  prominence  through  this  irritation  ; 
the  contraction  in  the  secondary  cataract,  too,  drags  on  the  sus- 
pensory ligament  and  the  ciliary  body,  and  provokes  a  chronic 
cyclitis.  In  consequence  of  all  this  the  adherent  fragments  may 
develop  into  a  tough  membrane,  and  the  eye  gradually  perish  by 
atrophy.  Fortunately,  however,  the  eye  in  most  cases  calms  down 
after  a  few  months,  so  that  the  operative  treatment  of  the  secondary 
cataract  may  be  discussed. 


-lens  l>e^rM 


Fig.  133. — Closure  of  the   Pupil  after   Extraction  of  Cataract.     {After  Pagenstecher  and 

Gentk.) 


The  treatment  is  discission.  After  thoroughly  atropinizing  the 
eye,  the  largest  possible  hole  in  the  membrane  should  be  torn  with  a 
discission  needle  or  cut  with  a  Graefe's  knife  exactly  at  the  center. 
If  the  membrane  is  so  tough  that  a  dangerous  dragging  on  the 
ciliary  body  is  to  be  feared,  dislaceration  should  be  substituted  for 
discission.  Dislaceration  consists  in  piercing  the  center  of  the 
membrane  with  two  needles,  and  then  by  a  leverage  motion  in 
tearing  as  large  a  hole  as  possible  from  the  center  toward  the  edge. 
Although  the  injury  itself  is  trifling,  there  is  developed  at  times 
after  operations  on  secondary  cataract  a  cyclitis  resulting  in  phthi- 
sis bulbi,  or  even  panophthalmitis.  One  must  be  careful,  therefore, 
not  to  operate  before  the  irritation  caused  by  the  first  operation 
has  completely  subsided.  On  the  other  hand,  the  delay  should 
not  be  unnecessarily  long,  since  a  recent  secondary  cataract  is  more 
delicate  than  an  old  one,  and  since  the  contraction  going  on  helps 


356  DISEASES    OF    THE    LENS. 

to  keep  open  a  hole  made  seasonably  enough.  If  the  wound  from 
the  first  operation  heals  kindly,  the  proper  time  for  discission  of 
the  secondary  cataract  will  be  about  two  months  afterward. 

Many  surgeons  say  that  division  of  the  secondary  cataract  by 
a  fine  scissors  forceps  introduced  into  the  anterior  chamber  is  free 
from  the  dangers  of  discission.  I  have  had  no  experience  in  this 
method. 

II.  APHAKIA. 

An  eye  from  whose  dioptric  system  the  crystalline  lens  has  been 
removed  is  called  aphakic.  All  eyes  operated  on  for  cataract  are 
therefore  in  this  condition.  The  absence  of  lens  can  be  recognized 
by  a  depth  of  the  anterior  chamber  and  by  a  tremulousness  of  the 
iris  in  case  it  is  not  adherent  to  the  secondary  cataract.  The  essen- 
tial proof  of  aphakia  lies  in  the  detection  of  the  absence  of  the 
Purkinje-Sanson's  lens-images.  Since  the  ophthalmologist  can 
easily  demonstrate  the  presence  or  absence  of  these  images  (/.  lod), 
the  detection  of  aphakia  is  correspondingly  easy.  With  focal  illu- 
mination we  see  in  the  pupil  the  shimmering  striations  of  the  pos- 
terior capsule  or  the  whitish  gray  stripes  of  the  anterior  capsule. 
Even  when  the  lens  has  been  removed  in  its  unruptured  capsule 
there  is  a  moderate  reflection  at  the  border  between  aqueous  and 
vitreous.  This  must  not  be  confused  with  the  lens-images :  there 
are  two  of  the  latter,  of  unequal  size, — the  anterior  image  making 
the  same  movements,  the  posterior  image  making  contrary  move- 
ments, if  the  illuminating  lens  is  moved  back  and  forth  in  its  own 
plane. 

The  refractive  power  of  the  lens  is  about  lo.o  Diopters,  and  this 
amount  of  power  is  lost  to  the  eye  by  a  cataract  operation.  An 
emmetropic  eye  becomes  therefore  in  its  aphakic  condition  one  of 
lo.o  D  Hyperopia.  An  axis  myopic  eye  of  4.0  D  becomes  jo.o  — 
^.o  =  6.0  D  hypermetropic.  A  hypermetropic  eye  of  ^.o  D  becomes 
1 0.0  -\-  4.0  =  i^.o  D  hypermetropic. 

The  manner  in  which  the  eye  is  robbed  of  its  lens  has  an  especial 
influence  on  the  refractive  condition.  A  horizontal  incision  almost 
always  flattens  the  cornea  in  healing  in  the  perpendicular  principal 
meridian,  and  the  result  is  a  corneal  astigmatism,  regular  in  the  best 
cases,  irregular  in  the  worst,  generally  both  regular  and  irregular. 

An  aphakic  person,  if  he  did  not  happen  to  have  a  myopia  of 
lo.o  D  before  the  operation,  cannot  see  distant  objects  distinctly, 
not  to  mention  near  ones ;  and  he  must  resort  to  cataract  glasses 


APHAKIA.  357 

{p.  j8  ct  seq).  If  the  astigmatism  is  regular,  the  lens  must  be 
ground  sphero-cylindrical.  A  moderate  degree  of  regular  astig- 
matism may  be  overcome  by  the  patient's  adjusting  his  glasses  in 
an  oblique  position  (/.  j/p).  When  the  lens  is  gone  the  eye  loses 
its  ability  to  accommodate  for  a  near  point.  To  take  the  place  of 
this  the  artifice  must  be  resorted  to  of  setting  the  glasses  further 
away  from  the  eye,  or  the  neutralizing  lens  must  be  exchanged  for 
stronger  ones.  For  example,  if  the  aphakic  person  has  a  hyper- 
opia of  lo.o  D,  his  eye  with  +/5.0  D  can  be  adjusted  for  about 
1-  i?i.  As  a  rule,  patients  learn  this  themselves,  and  they  make  an 
adjustment  for  middle  distance  by  placing  the  glasses  lower  down 
on  the  nose. 

The  statement  that  the  effect  of  a  convex  lens  is  increased  by  setting  it  further  from 
the  eye  is  generally  true  only  under  the  assumption  that  the  object  lies  at  a  greater  dis- 
tance than  twice  the  focal  distance  of  the  lens.  In  aphakic  persons  this  condition  is 
fulfilled ;  not  so  in  emmetropic  presbyopia.  In  this  latter  condition,  therefore,  to  set  the 
glasses  further  off  does  not  increase,  but  does  on  the  contrary  decrease  the  convergence 
of  the  luminous  rays.  Examples :  An  emmetrope  with  the  lens  removed  reads  at  2^  cm. 
with  -\-r4.0  D  ;  the  book  is  therefore  removed  more  than  twice  the  focal  distance  of  the 
lens  ;  for  the  focal  distance  is ;^=  7  cm.,  twice  this  distance  equals  14  cm.  An  em- 
metropic presbyope  reads  at  2^  cm.  with  -\-4.0  D\  the  book  is  therefore  not  twice  the 
focal  distance  of  the  lens,  for ^=  2j  cm.,  and  twice  this  equals  jo  cm. 

That  setting  the  glasses  further  from  the  eye  increases  their  effect,  if  the  object  is 
removed  more  than  twice  the  focal  distance  of  the  lens,  depends  upon  the  following  easily 
demonstrated  fact :  if  the  object  is  to  the  left  at  a  great  distance,  the  lens  throws  an  image 
to  the  riglit  nearly  at  its  focal  point.  If  I  move  the  lens  toward  the  left,  the  image 
passes — toward  the  right  if  reckoned  from  the  lens,  but — in  space  with  the  lens  toward 
the  left  until  the  distance  between  object  and  lens  equals  twice  the  focal  distance ;  if 
the  lens  is  moved  still  further  toward  the  left,  the  image  passes  toward  the  right  away 
from  the  lens,  so  that  from  now  on  it  passes  toward  the  right  in  space. 

The  proof  of  this  statement  cannot  be  given  in  an  elementary  way. 

From  what  has  been  said  above,  it  is  clear  that  an  aphakic  person  can  see  as  well  with 
the  glasses  bought  of  the  optician  as  he  sees  through  the  trial  lens  used  by  the  surgeon 
only  when  the  spectacles  purchased  by  him  are  set  as  far  from  the  eye  as  the  lenses  were 
in  the  trial  frame  of  the  surgeon.  We  must  not  neglect,  therefore,  to  give  the  optician 
some  suggestion  concerning  the  desired  distance  at  which  the  glasses  should  rest  in  front 
of  the  eye.  This  is  of  particular  importance  in  sphero-cylindrical  glasses.  The  rea- 
sons cannot  be  explained  in  a  few  words. 

Visual  acuity  of  an  aphakic  person  appears  at  the  test  greater 
than  it  actually  is,  because  the  letters  seem  enlarged.  The  nodal 
point  of  the  new  dioptric  system — cataract  glass  plus  aphakic  eye 
— lies  further  in  front  of  the  retina  than  it  does  in  the  normal  eye, 
and  therefore  everything  is  presented  to  the  aphakic  eye  at  a  larger 
visual  angle. 


358  DISEASES    OF   THE    LENS. 

The  aphakic  eye  suffers  at  times  from  dazzHng.  This  is  due  in 
part  to  the  aperture  in  the  iris  made  for  the  extraction  of  the  cata- 
ract. Another  reason  may  be  found  in  the  reflection  produced  on 
the  curved  surfaces  of  the  cataract  glasses.  Many  patients  com- 
plain about  occasional  red  vision,  erytliropsia,  which  appears  inci- 
dentally when  looking  at  bright  surfaces.  Perhaps  red  vision  may 
be  but  a  kind  of  dazzling.  It  disappears  after  a  time.  In  one  case 
I  noticed  rapid  improvement  after  using  iodid  of  potassium.  Sug- 
gestion ? 


III.  CHANGES  OF  POSITION  OF  THE  LENS. 
I.  Ectopia     Lentis    {^Congenital    Dislocation). — This     anomaly 
occurs  usually  on  both  sides  symmetrically.     It  is  most  common 
upward.     Becker  explains   the  condition   as  due  to  an    unequal 


Fig.  134. — Downward  Displacement  of  the  Lens,  under  Transillumination.    {After  Jaeger.) 

development  of  the  suspensory  ligament.  A  displacement  of  the 
lens  effects  a  decided  disturbance  of  vision  which  can  be  improved 
in  some  cases  by  concave,  in  other  cases  by  cylindrical  lenses.  If 
the  pupil  is  so  large  or  the  displacement  so  pronounced  that  the 
edge  of  the  lens  presents  within  the  pupillary  area  {^Fig.  134),  the 
result  is  "  double  vision  in  one  eye,"  although  it  is  not  necessary 
that  the  double  images  be  perceived  by  the  patient's  consciousness. 
It  depends  on  the  distance  of  the  object  whether  one  of  the  images 
is  more  hazy  than  the  other,  and  whether  or  not  it  is  therefore 
neglected  or  excluded.  Luminous  rays  from  infinity  striking  that 
part  of  the  pupil  which  has  no  lens  are  focused  at  a  point  behind 
the  retina,  while,  on  the  contrary,  rays  passing  through  the  edge  of 
the  retina  may  be  focused  in  front  of  the  retina.  If  the  object  fixed 
lies  at  a  proper  distance,  rays  refracted  at  the  edge  of  the  lens  are 


HYPEROPIA.  ^Gt, 

I.  HYPEROPIA  (Farsightedness),  H. 

Complaints  of  farsightedness  are  various.  Many  patients  seek 
aid  because,  after  a  period  of  reading  and  writing,  the  letters  run 
into  one  another,  and  are  so  confusing  as  to  become  illegible. 
The  patients  must  stop  to  rub  their  eyes ;  but  the  same  trouble 
comes  anew  and  is  intensified  by  burning,  pressure  on  the  eyes,  or 
even  headache  ;  these  necessary  interruptions  occur  more  frequently 
until  the  book  or  work  is  laid  aside.  Others  complain  chiefly  of 
headache,  and  say  that  the  family  physician  sent  them  because  he 
thought  that  this  headache  was  due  to  the  eyes.  Such  troubles 
are  called  "  accommodative  asthenopia!'  ^  They  arise  from  exhaus- 
tion of  the  muscle  of  accommodation,  which  persists  in  continued 
contraction  even  if  the  hyperope  tries  to  look  at  distant  objects.  If 
now  this  hyperope  uses  his  eyes  for  a  near  point — reads  or  writes, 
for  example, — there  is  demanded  of  his  muscle  of  accommodation 
a  further  contraction,  which,  this  having  already  approached  the 
maximum,  is  greater  than  can  be  continuously  maintained.  Indis- 
tinct vision  will  be  added  to  the  feeling  of  strain. 

Asthenopia  and  indistinct  vision  appear  in  many  cases  earlier 
than  might  be  expected  from  what  is  said  above,  because  the  rela- 
tive range  of  accommodation  ( p.  80  et  seg.)  is  no  longer  extensive 
enough.  For  example,  a  person  twenty  years  old  with  2.0  D  of 
hyperopia  would  be  able  to  work  (with  one  eye)  at  jj  cm.  distance 
without  discomfort,  since  in  this  case  he  uses  ■?  +  J  =  J"  Diopters, 
that  is,  only  one-half  of  his  range  of  accommodation  of  lo.o  D. 
But  with  an  accommodative  act  of  5.0  D  there  is  associated  a  con- 
vergence only  to  a  point  —  m.  =  20  cm.  distant.  Consequently, 
in  that  accommodative  act  of  5.0  D,  2.0  D  belong  to  the  positive 
interval  of  accommodation  which  are  applied  to  convergence  at 
—  m.     Both  eyes  are  fit  for  use,  however,  only  if  the  positive 

interval  of  the  accommodation  applied  (to  convergence  at  —  m!) 
is  considerably  greater  than  2.0  D.  If  this  is  not  the  case,  the 
patient  can  avoid  asthenopia  in  two  ways  :  He  may  give  up  short 
dioptric  adjustment,  and  be  content  with  binocular  vision  while 
seeing  everything  with  circles   of  diffusion  ;  or  the  necessity  for 

'  There  is  a  muscular  asthenopia  that  produces  the  same  symptoms  (/.  j6(?)  ;  and  a 
conjunctival  (/.  1S3),  a  nervous  (^.  v.')  or  retinal  (/.  joj)  asthenopia. 


364  ERRORS    OF    REFRACTION. 

accurate  vision  may  predominate,  and  accurate  dioptric  adjustment 
will  be  obtained,  but  with  deviation  of  one  eye  inward,  that  is, 
with  sacrifice  of  binocular  vision.  Since  the  second  way  is  often 
(unconsciously)  chosen  by  the  patient,  hyperopia  becomes  one  of 
the  most  common  causes  of  internal  squint  {q.  v.). 

It  has  been  said  that  complaints  about  farsightedness  are  various.  It  sometimes  hap- 
pens that  the  complaint  is  made,  not  of  farsightedness  but 'of  nearsightedness.  The 
patient  holds  his  book  or  other  objects  close  to  his  eyes.  The  explanation  is  simple.  If 
the  hj-peropia  is  pronounced,  the  range  of  accommodation  is  not  great  enough  to  neutral- 
ize it  and  to  adjust  vision  for  a  near  point  at  the  same  time.  The  patient,  therefore, 
gives  up  any  attempt  at  exact  dioptric  adjustment,  and  prefers  to  replace  it  by  enlarge- 
ment of  the  visual  angle.  By  bringing  the  object  close  to  his  eye  this  visual  angle 
increases  more  rapidly  than  do  the  circles  of  diffusion,  and  the  pupils  become  so  con- 
tracted that  the  latter  dioptric  error  is  somewhat  minimized. 

It  happens  also  that  the  symptoms  do  not  refer  at  all  to  vision,  but  to  burning  in  the 
eyes  and  to  their  sticking  together,  all  of  which  is  apparently  explainable  by  the  inflamed 
condition  of  the  conjunctiva  and  lids.  The  usual  treatment  for  such  trouble  is,  however, 
futile,  because  a  hyperopia  or  an  astigmatism  is  at  the  bottom  of  it.  Donders  insisted 
on  examining  the  refractive  condition  in  every  disease  of  the  eye,  a  step  not  always  taken 
nowadays  by  the  practising  ophthalmologist,  but  the  experienced  observer  will  never 
neglect  such  an  examination  if  he  finds  that  a  conjunctival  or  palpebral  irritation  resists 
ordinary  treatment. 

The  distress  from  hyperopia  drives  the  patient,  who  has  been  far- 
sighted  from  his  youth,  to  the  physician,  at  different  ages.  This 
depends  on  several  circumstances — the  degree  of  hyperopia  first  of 
all.  Slight  hyperopia  up  to  2.0  D  will  be  tolerated  longer  than 
moderate  hyperopia,  2.0  D  to  5.0  D,  or  than  pronounced  hyperopia 
of  more  than  5,0  D.  The  range  of  accommodation  present,  that 
is,  the  age  of  the  patient,  is  the  next  important  factor.  The  third 
is  the  occupation  of  the  individual ;  the  tiller  of  the  soil  is  less 
troubled  by  his  hyperopia  than  the  clerk,  the  seamstress,  or  the 
delicate  artisan.  Finally  comes  the  general  health ;  those  who 
have  tolerated  their  hyperopia  without  complaint  become  asthen- 
opic  after  an  exhausting  illness. 

Anatomy. — It  has  been  said  that  hyperopia  depends  upon  the 
shape  of  the  eyeball.  The  hyperopic  eye  is  smaller  than  normal 
in  all  diameters ;  it  may  therefore  be  considered  an  incompletely 
developed  organ.  The  sclera  is  flat  near  the  cornea,  sharply  curved 
near  the  equator.  The  anterior  chamber  is  shallow.  The  visual 
axis  cuts  the  cornea  at  a  point  lying  relatively  near  the  nasal  side 
of  t"he  center  of  the  cornea;  the  angle  gamma  {p.  84)  is  large,  about 
7°.     Since  the  position  of  the  two  eyes  is  estimated  rather  accord- 


ANATOMY.  365 

ing  to  the  direction  of  the  corneal  apices  than  to  that  of  the  visual 
axes,  two  eyes  with  a  large  angle  gamma  give  us  the  impression  of 
divergence.  The  sclera  is  thick  and  consequently  pure  white,  in 
contrast  to  the  bluish  appearance  of  the  sclera  in  a  myopic  eye. 
Although  a  skilled  observer  may  make  a  guess  at  hyperopia  from 
these  signs  alone,  the  diagnosis  must  be  supported  by  the  objec- 
tive (/>.  iz^")  and  subjective  (/.  J7)  examinations,  while  the  visual 
acuity  can  be  estimated  at  the  same  time.  It  is  a  regular  result  to 
find  that  pronounced  hyperopia  is  associated  with  a  reduced  visual 
acuity.  The  reason  lies  in  the  corneal  astigmatism,  which  of  itself 
characterizes  the  hyperopic  eye  as  incompletely  developed.  The 
range  of  accommodation  in  pronounced  hyperopia  may  be  less  than 
the  normal,  in  consequence  of  insufficient  development  of  the 
ciliary  muscle ;  and  in  the  same  way  the  range  of  movement  (ex- 
cursion) of  the  two  eyes  may  suffer  by  faulty  development  of  the 
eye-muscles. 

After  measuring  the  visual  acuity  and  hyperopia  of  each  eye 
separately,  the  two  eyes  together  should  be  tested.  It  will  often 
be  found  that  the  manifest  hyperopia  in  two  eyes  is  o.j,  o.jj,  or 
even  i.o  D  greater  than  in  each  eye  alone.  The  result  of  the  test 
of  both  eyes  together  indicates  the  glasses  to  be  worn. 

In  myopia  also  there  is  found  at  times  a  weaker  refractive  condition,  that  is,  a  lower 
degree  of  myopia  when  both  eyes  are  used  than  with  one  eye.  How  can  that  be  ex- 
plained ?  Many  think  that  the  refractive  condition  found  in  one  eye  alone  is  the  correct 
one,  and  that  the  acceptance  of  stronger  convex  or  weaker  concave  lenses  at  the  test 
with  both  eyes  together  rests  on  an  error  which  is  counterbalanced  by  greater  visual 
acuity  of  both  eyes  together  contrasted  with  the  lesser  visual  acuity  of  a  single  eye. 
Others  think  that  the  refractive  condition  found  in  both  eyes  together  is  the  correct  one, 
and  that  the  weaker  hyperopia  or  the  stronger  myopia  of  the  test  with  one  eye  alone  is 
confused  by  a  spasm  of  accommodation.  Neither  of  these  views  seems  to  me  to  settle 
the  question. 

Another  strange  fact  is  the  following.  It  not  seldom  happens  that  a  hyperope,  in 
spite  of  a  range  of  accommodation  greater  than  his  hyperopia,  and  in  spite  of  the  closure 
of  one  eye,  sees  with  the  other  eye  distant  objects  very  poorly  without  a  convex  lens. 
One  would  suppose  that  a  hyperope  with  2.0  D  oi  hyperopia  and  j.o  D  range  of  accom- 
modation would  always  be  able  with  one  eye  to  neutralize  his  2.0  D  of  hyperopia  by  a 
corresponding  effort  at  accommodation.  Why  is  this  not  possible  for  many  such  hyper- 
opes  ?  This  question  is  answered  by  some  authorities  as  follows :  When  a  child  has 
learned  to  use  his  eye — that  is,  in  his  earliest  years — he  has  a  range  of  accommodation 
of  about  20.0  D.  If  the  child  is  hyperopic,  he  is  accustomed,  when  looking  at  distant 
objects,  to  contract  his  ciliary  muscle  just  enough  to  neutralize  his  hyperopia.  The 
degree  of  contraction  necessary  for  this  is  said  to  be  exercised  instinctively  or  even 
against  the  will,  the  whole  life  long,  whenever  a  distant  object  is  looked  at.  Accord- 
ingly the  entire  hyperopia  is  said  to  remain   latent  during  life  just  as   it   was  in  youth, 


366  ERRORS    OF    REFRACTION. 

when  the  range  of  accommodation  remains  unchanged.  This  cannot  be  the  case,  how- 
ever. Since  the  range  of  accommodation  does,  on  the  contrary,  decrease  from  year  to 
year  (/.  ^j),  the  dioptric  result  of  such  an  unchanged  muscular  contraction  must,  in  a 
corresponding  degree,  decrease  ;  in  other  words,  only  a  portion  of  the  total  hyperopia  is 
latent,  another  portion,  increasing  with  years,  is  manifest.  In  old  age,  when  the  range 
of  accommodation  has  noticeably  decreased,  the  contraction  of  the  ciliary  muscle  pro- 
duces no  result  worth  mentioning,  and  consequently  the  entire  hyperopia  becomes 
manifest. 

Undoubtedly  the  idea  here  developed  is  the  correct  one,  but  it  does  not  exhaust  the 
subject.  As  a  matter  of  fact,  it  is  not  true  that  every  twenty-year-old  hyperope  has  one- 
half  of  his  hyperopia  latent,  the  other  half  manifest.  There  are  plenty  of  hyperopes  who, 
either  with  or  without  the  neutralizing  convex  lens,  can  adjust  their  eyes  for  distant 
vision;  their  hyperopia  is  therefore  "  faruZ/a/ive."  In  others,  even  in  the  twentieth 
year,  the  entire,  or  nearly  the  entire  hyperopia  is  latent.  In  still  others,  even  in  early 
youth,  the  entire  or  nearly  the  entire  hyperopia  is  manifest.  This  is  all  easily  explained 
if  we  consider  that  the  impulse  of  the  will  is  not  alone  determined  by  what  has  become 
habit  in  early  life,  but  may  also  be  modified  later  in  life  by  the  necessities  of  occupation 
and  the  activity  of  the  muscle  itself. 

Treatment. — A  cure  of  hyperopia  by  art  is  impossible.  Nature 
is  able,  however,  to  change  a  young,  hyperopic  eye  into  an  emme- 
tropic or  even  into  a  myopic  eye,  in  the  course  of  the  body's 
development.  This  is  not  the  case  in  the  adult.  Treatment  must 
therefore  be  confined  to  overcoming  the  complaints  of  the  patient 
by  suitable  lenses.  But  not  every  hyperope  has  symptoms.  Young 
persons  with  slight  hyperopia  (up  to  2.0  D)  can  usually  see  well 
both  near  and  far  objects.  They  need  no  treatment.  Not  until  the 
range  of  accommodation  decreases  is  asthenopia  added  to  slight 
hyperopia.  Such  cases  are  aided  by  suitable  reading  glasses. 
Until  the  fortieth  or  forty-fifth  year  those  glasses  which  just  neu- 
tralize the  hyperopia,  will,  as  a  rule,  suffice.  Beyond  the  forty-fifth 
year  reading  glasses  must  replace  the  diminished  range  of  accom- 
modation, and  must  therefore  be  the  stronger  the  older  the  patient. 
It  is  a  good  rule  that  the  patient  should  read  with  his  glasses  at 
the  usual  distance,  without  calling  into  play  any  more  than  two- 
thirds  of  his  range  of  accommodation.  For  example,  a  man  of 
fifty  years  with  hyperopia  of  2.0  D  is  accustomed  to  read  his  news- 
paper at  JO  cm.  distance ;  he  has  at  that  age  a  range  of  accommo- 
dation of  2.^  D.  To  adjust  his  eyes  for  jo  cm.  the  refractive 
strength  of  his  eyes  at  rest  must  be  increased  by -?  +  -'^=^.jj  D. 
But  with  this  increase  his  accommodative  mechanism  can  only 
take  part  to  the  extent  of  ■§•  of  2.^  D  =  7.75  D  (in  round  numbers). 
The  balance,  j.jj  —  i.y^z=j.^  D  (in  round  numbers)  must  be 
supplied  by  glasses. 


MYOPIA.  367 

In  many  cases,  especially  of  moderate  {2.0  to  5.0  D),  and  strong 
(over  j.o  D)  hyperopia,  vision  is  indistinct  for  distance  with  both 
eyes  together,  either  because  the  range  of  accommodation  is  not 
extensive  enough  to  adjust  the  eye  for  parallel  rays — absolute 
hyperopia,  or  because  such  an  extensive  contraction  of  the  accom- 
modative muscle  prevents  a  parallelism  of  the  visual  axes  {p.  yg). 
In  this  case  the  patient  must  wear  glasses  continuously.  If  there 
is  presbyopia  as  well,  he  must  have  two  pairs  of  glasses,  neutraliz- 
ing lenses  for  distant,  and  stronger  ones  for  near  objects.  In 
ordering  glasses  it  must  be  stated  that  the  distance  of  each  lens 
from  the  other  equals  the  pupillary  distance,  for  otherwise  an  arti- 
ficial "muscular  asthenopia  "  (/>.  j68)  will  result.  The  stronger 
the  lenses,  the  greater  is  the  prismatic  effect, 
and  therefore  the  more  significance  has  the 
distance  of  the  lenses  from  each  other. 

It  takes  a  long  time  for  some  persons  to  get 
accustomed  to  the  inconv^eniences  of  glasses — 
the  dazzling,  the  pressure  on  the  nose  and  behind 
the  ears,  and  the  distortion  of  objects  to  one  side. 
This  last  may  be  somewhat  avoided  by  using 
biconvex  and  biconcave  lenses,  the  so-called 
meniscus  glass,  which,  according  as  the  convexity 

{rlg.   IJj,  a)  or    the    concavity  {rig.   IJ^,  O)  is   the  ing,   {*)   Dispersing 

.  .  Meniscus. 

Stronger,  acts  as  a  collecting  or  dispersing  lens. 

Such  lenses  are  called  "  periscopic,"  because  sharp  retinal  images 

are  formed  even  if  lens  and  eye  are  not  exactly  centered. 


II.  MYOPIA  (Shortsightedness),  M. 

Symptoms. — Slight  myopia  up  to  2.0  D  is  often  tolerated  with- 
out complaint  or  even  suspicion.  An  accidental  examination  may 
be  the  first  means  of  discovering  the  shortsightedness,  and  of  show- 
ing the  patient  the  treasures  of  nature  and  art  that  may  have  been 
lost  to  him. 

In  moderate  myopia,  2.0  D  to  j.o  D,  the  visual  disturbance  is  so 
noticeable  that  the  patient  himself  must  see  how  defective  he  is  in 
comparison  to  his  fellowmen.  He  applies  therefore  to  the  physi- 
cian with  the  complaint  that  he  sees  poorly,  or  that  he  needs  glasses 
because  he  is  shortsighted.     In  other  cases  it  is  pain,  photophobia, 


368  ERRORS    OF    REFRACTION. 

and  inability  to  work  for  which  he  seeks  aid.  These  symptoms 
depend  partly  upon  muscular  asthenopia,  a  painful  exhaustion  of 
both  internal  recti.  The  myope  brings  everything  that  he  wishes 
to  see  distinctly  so  close  to  his  eyes  that  it  lies  at,  or  even  within, 
his  far-point  distance.  He  therefore  makes  such  great  demands 
upon  convergence  that  even  normal  eyes  could  not  stand  such  a 
continuous  strain.  It  happens,  moreover,  that  convergence  is  very 
difficult  for  axis-myopic  eyes,  on  various  grounds :  First,  because 
of  the  disproportion  between  the  required  accommodation  and  the 
convergence  (see  Causes  of  Concomitant  Squint) ;  second,  because 
of  the  length  of  the  eyeball,  which  renders  all  movements,  espe- 
cially that  for  convergence,  difficult,  since  long  eyeballs  would 
naturally  lie  with  their  long  axes  in  the  direction  of  the  orbits, 
which  would  bring  them  distinctly  divergent.  Other  cases  come 
to  the  physician  on  account  of  "flying  specks;"  the  myopic  eye  is 
to  some  extent  in  the  condition  in  which  it  would  be  artificially 
placed  if  one  wished  to  examine  himself  for  entoptic  opacities. 
Therefore,  in  many  myopes,  this  seeing  of  specks  ceases  when  the 
more  diffiise  illumination  of  the  retina  is  changed  to  sharp  images 
on  the  retina  by  concave  lenses. 

In  pronounced  myopia,  from  7.0  D  upward,  there  are  symptoms 
that  are  partly  dependent  upon  the  refractive  error  itself,  and  are 
partly  the  direct  consequence  of  it.  One  direct  result  is  the 
reduced  visual  acuity,  which  cannot  be  improved  even  by  neutraliz- 
ing lenses.  The  posterior  nodal  point  of  the  combined  system — 
eye  plus  concave  lens — lies  nearer  to  the  retina  than  it  does  in 
the  eye  alone ;  consequently  external  objects  appear  under  a 
visual  angle,  smaller  in  proportion  as  the  neutralizing  lens  is 
stronger,  that  is,  the  higher  the  myopia  the  smaller  the  visual 
angle.  But  a  more  important  factor  is  the  reduction  of  visual 
acuity  as  a  consequence  of  the  stretching  of  the  retina  '  and  impair- 
ment of  the  macula  lutea.  The  appearance  of  macular  changes  is 
often  first  noticed  by  the  patient  as  distortion  of  images,  metamor- 
pJiopsia.  Other  occasional  symptoms  of  pronounced  myopia  may 
be  mentioned,  such  as  the  light  phenomena  or  photopsia,  disturb- 
ances of  light  perception,  and  dark  spots  in  the  field  of  vision. 


^  In  a  stretched  retina  the  individual  optic-nerve  cells  lie  further  apart  than  normal ; 
consequently  a  retinal  image  must  be  larger  than  normal,  in  order  to  cover  a  sufficient 
number  of  these  cells. 


ANATOMY.  369 

Anatomy. — The  shortsighted  eye  is  enlarged,  generally  from 
before  backward,  less  often  in  all  directions.  An  enlargement  of 
the  latter  kind  is  called  buphthalmos.  An  enlarged  eye  protrudes 
from  the  eyeball,  and  is  less  movable  than  the  emmetropic  or  the 
small,  hyperopic  eye.  An  eye  enlarged  only  from  before  backward 
is  egg-shaped,  and  may  often  be  recognized  in  the  individual 
{p.  Jo).  Bonders  has  demonstrated  an  increase  in  the  diameter 
of  the  eyeball  as  great  as  jj  mm.,  Arlt  even  to  j/  mm.,  the  normal 
length  from  corneal  apex  to  posterior  surface  of  sclera  being 
2^.j  mm.  At  times  only  the  region  of  the  posterior  pole  bulges 
out,  sclerectasia  posterior ;  the  form  of  the  eyeball  is  then  obviously 
irregular.  Another  peculiarity  lies  in  the  fact  that  the  angle  between 
visual  line  and  axis  passing  through  the  corneal  apex  (angle  gamma) 
is  small  or  even  negative,  that  is,  that  the  visual  line  (and  visual 
axis)  passes  through  the  temporal  side  of  the  cornea.  This  condi- 
tion may  simulate  convergent  squint. 

The  diameter  of  the  pupil  in  myopia  is  said  to  be  on  the  average 
greater  than  in  other  refractive  conditions,  although  this  statement 
has  been  recently  disputed. 

The  lens  lies  deeper  than  in  emmetropia  or  hyperopia,  as  may 
be  recognized  by  the  depth  of  the  anterior  chamber,  and  occasion- 
ally by  tremulousness  of  the  iris.  The  sclera  of  the  myopic  eye  is 
thin,  often  no  thicker  than  paper  at  the  bulging  posterior  pole.  The 
vascular  coat  beneath  may  shimmer  through  a  thin  sclera,  so  that 
the  "  white  of  the  eye  "  often  appears  bluish-white  in  a  myopic 
person. 

The  ciliary  muscle  is  differently  constructed  than  it  is  in  emme- 
tropia or  hyperopia.  It  consists  almost  exclusively  of  meridional 
muscular  fibers  (Bruecke's  muscle,  Fig.  g^,  p.  266),  which  form  a 
powerful  band  extending  much  further  backward  than  normal. 
In  the  choroid  there  are  atrophic  areas,  especially  abundant  in  the 
immediate  neighborhood  of  the  optic  nerve,  sclero-choroiditis  pos- 
terior {staphyloma  posticum}  conus),  less  frequently  at  the  macula 
lutea,  and  occasionally  at  other  places  at  random,  choroiditis  dis- 
seminata. The  changes  in  the  choroid  can  be  seen  with  the  oph- 
thalmoscope during  life. 


^  The  name  really  refers  to  the  bulging  of  the  sclera,  but  is  also  used  to  describe  the 
atrophic  areas   of  the   choroid.     Staphyloma    posticum  is,   moreover,  not  restricted   to 
myopic  eyes,  but  is  seen,  though  less  frequently,  in  emmetropic  and  hyperopic  eyes. 
24 


370  ERRORS    OF    REFRACTION. 

The  illustrations,  Figs.  ij6  and  ijy,  show  a  sickle-shaped  and  a 
cone-shaped  staphyloma  posticum  at  the,  temporal  side  of  the  optic 
disc.  In  the  latter  there  is  a  sickle-shaped,  white  portion  sharply 
demarcated  from  a  cone-shaped,  black-spotted  portion.  Within  the 
area  of  the  pure  white  crescent,  the  choroid  and  pigment  epithelium 
have  completely  disappeared  and  the  sclera  is  quite  exposed.  As 
it  develops,  the  staphyloma  gradually  involves  the  nasal  side  of  the 
disc,  until  the  crescent  becomes  a  circle. 

Another  common  sign  in  myopia  is  an  egg-shaped  pupil,  with 
the  long  diameter  perpendicular.  This  oval  appearance  probably 
depends  upon  certain  anatomical  changes, — a  contraction  of  the 
optic  nerve  papilla  {Fig.  ij8)  and  the  choroid  toward  the  temporal 
side. 


Fig.  136. — Sickle-Shaped  Staphyloma  Posticum,  Upright  Image.     (A/ter  Jaeger.) 

The  vitreous  is  fluid,  and  there  are  floating  in  it  a  few  fibers  and 
flakes  which  may  be  recognized  as  vitreous  opacities  with  proper 
magnification  in  the  ophthalmoscope.  At  times  the  vitreous  is 
separated  from  the  posterior  pole  by  a  layer  of  fluid,  posterior  de- 
tachment of  the  vitreous  {Fig.  ij8).  The  vitreous  may  also  be  de- 
tached from   the   lens  in  front,  anterior  detachment  of  the  vitreous 

[Fig-  ijsy 

The  optic  nerve  sheath  is  reddened,  neuritis  myopjim.  The  intra- 
membranous  space  about  the  optic  papilla  is  noticeably  widened 
{Fig.  138).      The  retinal    vessels  have  a  somewhat  more  direct 


COURSE.  371 

course,  due  to  the  tension  of  the  retina.  In  the  area  of  a  staphy- 
loma the  pigment  epithelium  and  the  layer  of  rods  and  cones  may 
have  disappeared,  and  a  dark  spot  (scotoma)  in  the  visual  field  will 
correspond  to  such  an  atrophic  retinal  area.  And  finally,  retinal 
hemorrhages  and  retinal  prolapses  (/>,  Jij)  may  be  mentioned  as 
results  of  pronounced  myopia. 

Course. — The  anatomical  changes  just  enumerated  are  not  pres- 
ent in  every  case  of  myopia.  They  develop,  however,  during  the 
course  of  years  in  which  slight  myopia  is  progressing  into  pro- 
nounced myopia.  This  point  is  the  most  important  in  the  discus- 
sion of  myopia,  its  tendency  to  progress.     This  is  strongest  from 


Fig.  137. — Cone-Shaped  Staphyloma  Posticum,  Upkight  Image.    (After  Jaeger.) 

puberty  to  about  the  twenty-second  year.  Fortunately,  the  ten- 
dency ceases  at  this  period  in  most  cases ;  it  becomes  stationary. 
After  this,  as  a  rule,  nothing  pathological  can  be  demonstrated  dur- 
ing life  except  a  staphyloma  posticum.  In  a  i&v^  cases,  however, 
myopia  continues  to  develop  after  the  body  has  reached  full  matu- 
rity, and  is  therefore  continuously  progressive.  During  its  increase, 
symptoms  like  pain,  sensitiveness  to  light,  and  lack  of  strength 
are  particularly  distressing.  The  advance  of  myopia  is  character- 
ized not  only  by  the  approach  of  the  far  point,  but  also  by  the 
appearance,  or  rather  the  increase,  of  the  choroidal  atrophy  and  the 
other  changes  in  the  fundus.     One  may  often  recognize  as  a  sup- 


3/2  ERRORS    OF    REFRACTION. 

plementary  condition  the  various  stages  of  progressive  myopia  by 
the  various  colored  or  pigmented  zones  that  compose  the  staphy- 
loma {Fig.  ijt).  a  sharp  outline  to  the  staphyloma  indicated  by 
a  black  pigment  zone  {Fig.  ij6)  denotes  a  pause  in  the  progression  ; 
small  blotches  near  the  staphyloma,  on  the  other  hand,  denote  a 
continued  progression  of  the  disease.  In  pronounced  myopia, 
particularly  if  it  continues  to  progress,  there  finally  result,  although 
it  may  not  be  till  advanced  life,  these  changes  in  the  retina  above 
enumerated,  through  which  complete  blindness,  or  at  least  destruc- 
tion of  direct  vision  (macula  affection)  is  accomplished. 

Pronounced  and  progressive  myopia  is,  by  many  ophthalmolo- 
gists, sharply  differentiated  from  the  relatively  benignant  form  of 
myopia,  which  becomes  stationary  in  adult  life ;  the  former  is  con- 


Ani^riar  deiadjnent  ^H6reouS. 


Pasttruir  dedzcfunent  ^Vi/reotu, 

Jrvadeneii  iniemtanirajtmu 
space. 

Fig.  138. — A  Myopic  Eyb. 

sidered  an  essential  inflammation  of  the  posterior  pole,  a  scleroiico- 
choroiditis  posterior.  In  favor  of  this  view  there  is  the  fact  that  the 
malignant,  progressive  myopia  is  found  among  country  people,  and 
even  in  children,  who  really  supply  only  a  small  proportion  of  the 
ordinary  cases  of  myopia.  (See  sections  on  Causes  and  Extent^ 
Such  a  differentiation  is,  after  all,  of  no  practical  significance,  since 
benignant  myopia  may  at  any  time  change  into  the  malignant,  pro- 
gressive form. 

Diagnosis. — The  fact  that  an  eye  sees  distant  objects  less  dis- 
tinctly than,  but  near  objects  quite  as  well  as,  the  normal  eye,  is  the 
proof  of  the  presence  of  myopia.  To  complete  the  diagnosis,  the 
degree  of  myopia  must  be  estimated.  The  objective  method  is 
given  on  /.  i§2,  the  subjective  method  on  /.  j/. 

Causes  and  Extent. — Myopia  is  a  very  common  and  wide- 
spread disease.     Native  peoples  are  comparatively  free  from  it,  and 


CAUSES    AND    EXTENT.  373 

in  that  respect,  at  least,  are  "  better  men  "  than  we  are.  In  cul- 
tured races,  only  the  age  of  childhood  is  free  from  myopia.  As 
soon  as  school-life  begins,  cases  of  myopia  show  themselves,  and 
increase  in  number  the  higher  in  school  the  children  advance.  H. 
Cohn  found 

in     5  village  schools,  1.4  per  cent. 

in  20  elementary  schools,    d.j  per  cent. 

in    2  higher  girls' schools,    7.7  per  cent. 

in    2  grammar  schools,      10.3  per  cent. 

in    2  preparatory  schools,  19.7  per  cent, 
.in     2  colleges,  26.2  per  cent,  myopic  !  ^ 

He  found  also  that  the  degree  of  myopia  increased  with  the 
length  of  the  period  of  school.  Axis-myopia  has,  therefore,  been 
called  school-myopia.* 

It  is  intended  to  imply  that  attendance  at  school  is  the  cause  of  myopia  because  dur- 
ing the  growth  and  development  of  the  general  system,  the  eye  is,  at  school,  compelled 
to  do  too  much  near  work.  This  near  work,  like  reading  and  writing,  acts  very  harm- 
fully. Boys  who  leave  school  when  fourteen  years  old,  to  become  tailors  or  watch- 
makers, continue  in  the  new  field  of  labor  to  strain  the  eyes  with  near  work,  but  experi- 
ence teaches  that,  in  spite  of  this  fact,  myopia  is  not  so  frequent  among  them  as  it  is 
among  their  former  comrades  remaining  at  school. 

The  essential  connection  between  school  work  and  the  lengthening  of  the  eyeball  is 
still  problematic.  An  assumption — unproved  as  yet — may  help  to  make  the  matter 
clear:  children,  when  reading  and  wTiting,  are  accustomed  to  bend  their  heads  forward 
to  bring  them  close  to  the  books.  In  many  this  is  due  to  poor  visual  acuity  from  astigma- 
tism or  corneal  opacities,  but  in  others  it  is  only  a  bad  habit.  The  eyes  are  made  strongly 
convergent,  the  visual  plane  is  lowered,  and  the  muscle  of  accommodation  is  kept  tense. 
On  account  of  the  convergence  the  interni  as  well  as  the  superior  and  inferior  recti  are 
kept  tense,  the  obliqui  and  inferior  recti  also,  by  the  lowering  of  the  visual  field.  The 
other  muscles  are  at  least  strained.  They  all  press  upon  the  eyeball  and  increase  its  in- 
ternal tension,  while  the  contraction  of  the  ciliary  muscle  has  the  same  effect.  The  eye 
becomes  overfilled  with  blood  by  the  hyperemia  from  work  on  the  one  hand,  and,  on  the 
other,  by  the  fact  that  with  the  head  bent  forward  the  return  of  venous  blood  from  the 
cranium  is  retarded.  It  may  be  seen  that  an  increased  internal  pressure  causes  the  eye's 
envelopes  to  yield,  although  this  does  not  explain  why  the  eye  is  lengthened  from  before 
backward  as  the  result  of  tension.  This  may  be  comprehended  by  studying  the  position 
and  the  necessary  action  of  both  obliqui.  They  surround  the  eye,  at  least  when  looking 
straight  ahead,  like  a  girdle,  and  must  therefore  press  it  into  the  shape  of  an  egg  if  the 

*  The  statistics  are  from  German  sources. — Translator. 

2  I  have  just  had  in  my  care  an  eight-year-old  boy  with  a  myopia  of  j'.  o  to  6.0  D,  very 
strong  for  his  age.  In  asking  him  about  it,  I  discovered  that  he  was  going  to  two  schools, 
the  usual  elementary  school  and  an  Italian  night  school,  for  his  father  was  Italian  and 
wished  the  boy  to  continue  his  native  tongue.     Was  this  cause  and  effect  ? 


374  ERRORS    OF    REFRACTION. 

contraction  is  sufficiently  strong.  In  looking  toward  the  median  line,  this  girdle-like 
action  is  less  marked,  but  in  doing  this  the  eye  is  drawn  forward,  and  consequently 
raised  from  the  fat  layer  in  the  orbit,  against  which  the  recti  muscles  are  trying  to  press 
the  posterior  pole;  this  posterior  pole  is  therefore  robbed  of  its  support,  and  a  bulging 
is  made  possible. 

Not  all  school  children,  not  even  all  gymnasium  pupils,  are  myopic.  We  must  there- 
fore assume  that  some  are,  some  are  not,  predisposed  to  myopia.  We  say  it  is  con- 
genital. What  is  this  congenital  predisposition  ?  Stilling  deserves  credit  for  having 
attracted  the  attention  of  ophthalmologists  to  the  great  differences  in  direction  and  inser- 
tion of  the  superior  oblique  tendon.  The  thickness  and  resistive  power  of  the  sclera 
differ  in  different  individuals.  There  are  probably  personal  differences  in  the  structure 
of  the  ciliary  muscles.  Even  supposing  that  a  ciliary  muscle  consisting  chiefly  of  meri- 
dional fibers  relaxes  the  Zonula  of  Zinn  quite  as  well  as  one  supplied  with  circular 
fibers,  there  can  be  no  doubt  that  the  other  mechanical  effects  of  each,  the  effect  upon 
the  sclera,  for  example,  will  be  quite  different.  The  smallness  of  the  angle  gamma  is  also 
an  anatomical  peculiarity  that,  by  making  convergence  difficult,  may  become  a  cause  of 
myopia.  Weiss  suggests  that  a  longer  or  shorter  optic  nerve  may  have  its  significance, 
since,  if  the  optic  nerve  is  short,  convergence  of  the  visual  axes  causes  tension  at  the 
posterior  pole,  and  aids  therefore  in  the  development  of  myopia.  Thus  we  see  that 
there  are  numerous  reasons  for  supposing  that  the  inclination  to  myopia  lies  in  inherited 
anatomical  peculiarities  of  the  eyeball  itself. 

Treatment. — Myopia  cannot  be  cured,  but  it  may  be  prevented. 
If  the  eye  is  used  only  for  distant  vision  it  will  not  become  myopic 
(neglecting  exceptional  cases).  In  a  cultured  people,  however,  school 
and  a  sacrifice  of  eyes  to  it  cannot  be  avoided.  The  school  must 
therefore  be  so  arranged  that  the  number  of  eyes  so  sacrificed  does 
not  pass  the  minimum.  In  Germany  and  Switzerland  this  arrange- 
ment has  not  up  to  now  been  satisfactorily  accomplished.  The 
rules  that  ought  to  govern  house  and  school  are  the  following : — 

(i)  The  quantity  of  the  customary  daily  work  should  be  reduced, 
especially  in  the  high  schools.  In  many  of  these,  upper-class  students 
have,  besides  the  six  school  hours,  five  to  seven  hours  more  of 
work  at  home,  that  is,  eleven  to  thirteen  hours  of  daily  near  work  ! 

(2)  Between  hours  of  work  at  school  and  at  home  there  should 
be  suitable  intermissions. 

(3)  At  home  and  at  school  the  student  should  work  only  in  good 
daylight  or  in  good  artificial  light. 

(4)  Books  should  be  large  enough,  and  printed  in  clear,  well-de- 
fined type. 

(5)  Students  should  have  their  work  at  a  distance  of  J5  to  /f.o  cm. 
from  the  eyes,  with  the  visual  plane  only  moderately  lowered,  and 
with  a  natural  position  of  head  and  body.  Benches  and  type 
should  be  properly  adjusted  for  this   purpose.     The    upright   is 


TREATMENT,  375 

better  than  the  usual  obh'que  style  of  writing.  This  perpendicular 
writing  is  particularly  advised  by  Schubert  and  others.  Undoubt- 
edly upright  writing  has  its  advantages,  but  the  most  important 
point  is,  after  all,  as  Ritzmann  observes,  that  the  teacher  should 
have  judgment  and  self-denial  enough  to  insist  with  an  iron  per- 
tinacity that  the  proper  distance  from  the  work  be  maintained  by 
the  students. 

It  is  the  parents'  duty  to  see  that  the  children  avoid  all  reading 
(novels  !)  and  writing  which  is  not  indispensable  for  their  advance- 
ment in  school.  All  these  rules  must  be  doubly  enforced  if  myopia 
is  already  present.  If  myopia  increases  in  spite  of  all,  a  long  rest 
should  be  ordered,  or  the  school  should  be  entirely  given  up.  The 
general  health  should  be  looked  after,  and  plenty  of  fresh  air  pro- 
vided. 

To  prevent  the  advance  of  myopia  some  recommend  atropin,  others  the  very  opposite, 
eserin.  One  claims  that  atropin  is  no  good,  another  that  eserin  is  of  lilie  value.  The 
advantage  gained  from  the  use  of  either  remedy  does  not  lie  in  the  remedy  itself,  Lut  in 
the  prolonged  cessation  from  near  work.  Atropin  is  useful  and  indicated  when  part  of 
the  myopia  is  apparent,  and  conditioned  by  spasm  of  the  ciliary  muscle.  Such  a  spasm 
disappears  only  after  continued  and  energetic  application  of  atropin. 

The  disadvantages  of  myopia  can  be,  in  part  at  least,  neutralized 
by  glasses.  Should  every  myope  wear  glasses  ?  No  ;  they  are  often 
harmful  and  unnecessary.  The  following  rules  will  generally  ap- 
ply :— 

Myopes  of  2.0  D  or  less,  who  have  no  trouble  at  near  work,  but 
wish  glasses  for  distant  vision,  should  wear  eyeglasses  and  not 
spectacles,  and  should  be  advised  to  use  them  only  for  distance. 
In  myopia  from  2.0  D  to  ^.o  D  or  5.0  D,  neutralizing  lenses  for 
both  near  and  distant  work  may  be  used,  assuming  that  the  range 
of  accommodation  is  still  large  enough,  and  that  the  patient  is 
young.  Spectacles  thus  allow  the  book  to  be  held  at  a  suitable 
distance  {^o  cm}),  and  they  prevent  too  strong  convergence.  Any 
muscular  asthenopia  is  at  the  same  time  combated,  first  by  a  de- 
mand for  more  powerful  accommodation,  and  the  greater  call  upon 
the  muscles  of  convergence  associated  with  it;  second,  by  the 
greater  working  distance  permitted,  that  is,  by  a  lessened  use  of 
convergence  ;  and  third,  by  placing  the  lenses  further  apart,  if  this 
seems  necessary,  since  by  having  the  patient  look  through  the 
inner  half  of  the  lenses  instead  of  through  their  center,  we  obtain 
the  effect  of  a  prism  in  the  position  of  abduction  (/,  pj). 


3/6  ERRORS    OF    REFRACTION. 

In  myopia  from  /j..o  D.  or 5.0  D  to  y.o  D  or  8.0  D,  glasses  for  near 
work  must  be  ordered  which  displace  the  far  point  to  about  70  an., 
and  additional  eyeglasses  for  distant  vision.  Suppose  there  is 
myopia  oi  6.0  D,  the  far  point  then  lies  at  only  m  =  16.66  cm., 
which  is  much  too  near  for  comfortable  convergence  ;  if  the  myopia 
is  reduced  by  a  lens  of  — -7.5  D  so  that  it  remains  2.5  D,  the  far  point 
now  lies  at  —  m  =  40  an.  At  this  distance  accommodation  is 
not  required,  and  only  moderate  convergence  is  necessitated.  If  the 
patient  intensifies  his  spectacles  by  adding  eye-glasses  of  — 2.^  D 
his  myopia  is  neutralized  and  distinct  distant  vision  is  made  possi- 
ble. 

With  myopia  higher  than  j.o  D  to  8.0  D,  the  same  plan  may  be 
pursued  if  no  pathological  condition  within  the  eye  prevents  the 
use  of  lenses,  or  if  the  patient — which  is  usually  the  case — is  doubly 
distressed  by  the  lenses.  In  pronounced  myopia  it  is  often  neces- 
sary to  give  up  glasses  altogether.  Such  a  condition  has  induced 
many  ophthalmic  surgeons  to  treat  pronounced  myopia  by  extract- 
ing the  lens.  This  method  is  still  the  subject  of  warm  discussion. 
I  have  recently  resorted  to  it.  My  first  result  was  very  encourag- 
ing ;  a  patient  had  before  the  operation  V  =  ~~,  with  — /5.0  D  3 
— 2.0  D  cyl ;  after  the  operation  V  ■= —^  with  -J-/.5  D  cyl.  When 
we  know  that  patients  often  refuse  to  wear  strong  concave  lenses, 
although  without  a  lens  they  may  not  have  even  -^  of  the  normal 
vision,  it  is  plain  that  the  removal  of  the  crystalline  lens  is  of  great 
advantage  to  the  patient. 

It  has  been  recently  stated,  by  American  ophthalmologists  particularly,  that  total  neu- 
tralization of  even  pronounced  myopia  was  not  only  possible  but  even  desirable ;  and 
that  the  patient's  original  repugnance  to  strong  glasses  would  disappear  after  using  them. 
My  experience  is  that  the  glasses  disappear  before  the  repugnance  does  I 


III.  ASTIGMATISM.     As. 

I.  REGULAR  ASTIGMATISM. 
The  normal  eye  is,  to  a  very  slight  degree,  regularly  astigmatic. 
This  can  be  called  physiological  astigmatism,  so  long  as  it  causes 
no  visual  disturbances  or  symptoms.  Such  a  definition  must,  to 
be  sure,  allow  an  astigmatism  of  0.75  D  to  be  at  one  time  physio- 
logical, at  another  pathological,  since  in  early  life,  so  long  as  the 


REGULAR    ASTIGMATISM,  377 

rancre  of  accommodation  is  large,  this  slight  astigmatism  may  cause 
no  disturbance,  but  in  the  thirties  it  may  lead  the  patient  to  the 
physician.  Astigmatism  of  more  than  1.5  D  always  causes  disturb- 
ance, even  in  youth.  In  physiological  astigmatism  the  perpendicu- 
lar meridian  is  the  meridian  of  strongest  curvature;  the  horizontal, 
that  of  weakest  curvature.  This  is  usually  the  case,  too,  in  patho- 
logical astigmatism.  It  is  seldom  the  reverse,  that  the  horizontal 
meridian  is  the  stronger  refractive,  such  a  case  being  spoken  of  as 
against  the  rule,  astigmatisnuis  peri'ersus.  It  does,  however,  happen 
often  enough  that  the  meridians  of  stronger  and  weaker  curvature 
are  not  exactly  perpendicular  and  horizontal,  but  are  more  or  less 
oblique. 

The  symptoms  of  an  astigmatic  consist  of  reduced  visual  acuity 
or  of  asthenopic  troubles,  or  of  both.  The  reduction  in  visual 
acuity  depends  upon  distortion  of  the  retinal  images  (/.  ^g).  The 
asthenopic  troubles  depend  in  part  upon  the  effort  the  individual 
makes  to  neutralize  his  astigmatism  by  unequal  contraction  of  his 
ciliary  muscle,  in  part  also  upon  the  fact  that  he  brings  objects 
nearer  to  his  eyes,  in  order  to  compensate  for  the  indistinctness  of 
these  retinal  images  by  increasing  the  visual  angle ;  but  in  doing 
this  he  uses  accommodation  and  convergence  improperly.  The 
increased  effort  necessitated  by  working  with  indistinct  retinal 
images  must  be  somewhat  of  a  factor  also.  Finally,  there  are  cases 
in  which  the  complaints  of  the  patient  do  not  immediately  suggest 
astigmatism,  but  are  classed  by  the  physician  among  diseases  of 
the  conjunctiva  {p.  gy). 

Anatomy. — The  total  astigmatism  of  an  eye  depends  partly  upon 
meridian-asymmetry  of  the  lens,  partly  upon  meridian-asymmetry 
of  the  cornea.  Corneal  astigmatism  being  the  stronger,  decides 
the  condition.  In  a  few  cases  it  is  increased  by  the  lenticular 
astigmatism,  but  in  most  cases  is  reduced  by  it ;  astigmatism  in  the 
lens  is,  therefore,  as  a  rule,  the  opposite  of  that  in  the  cornea. 

Corneal  astigmatism  may  be  congenital  or  acquired — usually 
congenital  in  eyes  highly  myopic.  In  early  life  astigmatism  is,  in 
most  cases,  "  with  the  rule."  In  the  course  of  years  the  form  of 
the  cornea  may  change  essentially  so  that  from  adult  life  on,  astig- 
matism against  the  rule  becomes  more  and  more  common.  Astig- 
matism is  acquired  after  certain  operations,  such  as  cataract 
extractions,  iridectomy  and  sclerotomy ;  some  months  after  the 
operation  it  is  less  than  at  first,  but  it  never  entirely  disappears. 


378  ERRORS    OF    REFRACTION. 

Lens  astigmatism — apart  from  any  congenital  meridian-asymmetry — 
may  be  due  to  some  acquired  obliquity  of  position  {p.  J38),  and  is 
then  particularly  strong. 

Diagnosis. — In  every  estimation  of  hyperopia  and  myopia  by 
means  of  lenses,  astigmatism  must  be  thought  of  if  perfect  visual 
acuity  is  not  obtained  with  the  ordinary  spherical  lenses.  It  is 
particularly  suspicious  if  in  the  rows  of  letters  of  different  sizes 
some  letters  are  read  correctly,  others  incorrectly.  The  character 
of  the  indistinctness  of  the  retinal  image,  and  the  form  of  the  letter 
itself,  will  give  some  clue  to  the  refractive  error.  For  example,  if 
the  retina  is  at  i"  {Fig.  12,  p.  ^8),^.  small  L  will  be  recognized 
more  easily  than  a  large  B,  because  in  the  L  the  perpendicular  line 
at  any  rate  is  distinct,  while  the  perpendicular  line  in  the  B  is  pro- 
portionally indistinct  on  account  of  the  three  confusing  horizontal 
elements  of  the  letter.  The  objective  demonstration  of  astigma- 
tism may  be  made  by  the  ophthalmoscope  (/.  128),  while  the  posi- 
tion of  the  principal  meridians  and  the  degrees  of  their  refraction 
may  be  determined  by  the  shadow  test  {p.  134).  Simple  corneal 
astigmatism  may  be  determined  by  the  keratoscope  (/>.  gf)  and 
measured  by  the  ophthalmometer  (/.  gS).  The  difference  between 
total  and  corneal  astigmatism  as  determined  by  keratoscope  or 
ophthalmometer  equals  the  lenticular  astigmatism. 

Treatment  of  astigmatism  consists  in  prescribing  the  proper 
neutralizing  cylindrical  lenses,  with  the  necessary  correction,  of 
course,  of  any  hyperopia  or  myopia  present.  If  there  is  mixed 
astigmatism  (/.  50),  two  cylinders  are  required,  one  convex  and 
the  other  concave,  their  axes  being  perpendicular  to  each  other. 
Instead  of  two  piano-cylindrical  lenses  with  their  plane  surfaces 
joined,  a  single  glass  may  be  used,  with  the  cylindrical  surfaces 
ground  upon  it. 

There  is,  in  general,  no  contraindication  to  the  use  of  cylindrical 
lenses.  In  spite  of  this,  however,  no  ophthalmologist  can  escape 
the  chagrin  of  seeing  a  patient  neglect  the  glasses  which  have  been 
selected  with  great  care  and  which  essentially  improved  the  vision. 
If  the  patient  is  asked  why  he  does  not  wear  these  glasses,  he  will 
answer  that  they  make  his  head  ache  or  cause  vertigo.  The  reason 
for  this  is  not  always  clear.  Much  depends  upon  having  the  axes 
of  cylindrical  lenses  correspond  exactly  with  the  principal  merid- 
ians of  the  eye.  For  this  purpose  test  frames  {Fig.  ijg)  have  been 
arranged  so  that  the  cylindrical  lenses  in  a  separate  clasp  can  be 


IRREGULAR    ASTIGMATISM.  379 

revolved  about  the  rigid  part  of  the  frame,  the  circumference  of 
which  is  divided  into  degrees.  The  best  position  for  the  cylinder 
must  be  found  by  trial,  and  the  position  of  its  axis  noted  on  the 
test  frame.  It  is  always  advisable  carefully  to  see  that  the  physi- 
cian's prescription  for  glasses  is  followed  by  the  optician  in  every 
detail  of  refraction,  position  of  axes,  pupillary  interval,  and  distance 
from  the  eyes.     Errors  are  not  uncommon. 

Just  as  astigmatism  may  be  caused  by  an  obliquity  of  the  cr}'s- 
talline  lens,  so  may  astigmatism  be  neutralized  by  holding  spherical 
lenses  obliquely  before  the  eyes.  Myopes  with  astigmatism  (astig- 
matismus  myopicus  compositus)  are  very  often  content  with  simple 
spherical  lenses,  for  they  have  noticed  by  accident  that  they  can  see 
much  better  when  looking  obliquely  through  their  glasses,  and  they 
make  practical  use  of  the  discovery  by  turning  the  head  in  one 
direction  and  the  eyes  in  the  other,  thus  looking  obliquely  through 
the  glasses. 

There  is  another  explanation  for  the  fact  that  myopes  are  inclined 


Fig.  139. — Rodknstock's  Test  Frame. 

to  look  obliquely  through  their  glasses.  In  many  cases  the  myope 
does  not  try  to  correct  astigmatism,  but  to  produce  it,  in  order  to 
acquire  better  visual  acuity.  Such  a  myope  has  too  weak  glasses  ; 
the  image  of  a  distant  object  still  falls  in  front  of  his  retina,  in  spite 
of  his  glasses,  while  on  the  retina  there  is  an  image  combined  with 
diffusion  circles.  If  now  such  a  myope  looks  obliquely  through 
his  glasses,  he  produces  an  astigmatism  in  which  each  luminous 
point  has  an  anterior  and  a  posterior  linear  focus,  the  posterior 
linear  focus  falling  (under  certain  conditions)  exactly  on  the  retina. 
Objects  whose  linear  prolongations  coincide  with  the  direction  of 
these  linear  foci  are  therefore  seen  more  distinctly  than  if  they  were 
looked  at  directly  through  the  glasses. 

2.  IRREGULAR  ASTIGMATISM. 
This  is  understood  to  signify  a  condition  of  the  dioptric  system 
in  which  there  is  no  image  formed  even  by  the  rays  of  a  homo- 
centric   pencil — that   is,  by  rays   falling   upon   the   same  principal 


380  ERRORS    OF    REFRACTION. 

meridian.  The  normal  eye  is  irregularly  astigmatic,  although  to  a 
slight  extent  only.  This  may  depend  upon  "  spherical  aberration," 
that  is,  upon  the  fact  that  luminous  rays  in  passing  through  a 
spherical  surface  are  united  the  sooner  the  greater  the  angle  of 
incidence ;  in  Fig.  1^0  angle  ^  is  greater  than  angle  a,  consequently 
the  image  b  is  nearer  to  the  refracting  surface  than  the  image  a. 
The  flattening  of  the  cornea  at  the  periphery  reduces  the  spherical 
aberration  of  the  eye  and  makes  it  to  some  extent  aplanatic,  while 
the  exclusion  of  the  excentric  incident  rays  by  the  iris  accom- 
plishes the  rest.  The  noticeable  irregular  astigmatism  of  a  healthy 
eye  depends  upon  the  structure  of  the  lens.  A  star  does  not  ap- 
pear to  us  as  a  luminous  point,  but  as  "  star-shaped  " — that  is,  as  a 
point  with  rays,  the  structure  of  the  crystalline  lens  being  responsi- 
ble for  the  condition.  In  the  aphakic  eye  this  phenomenon  is  not 
present. 

Irregular  astigmatism  of  pathological  nature  causes  reduction  of 

visual  acuity  below  the  normal.  Sul- 
zer  assumes  that  the  extraordinarily 
numerous  cases  of  imperfect  visual 
acuity  without  visible  cause  depend 
upon  irregular  curvature  of  the  cor- 
nea.    The  same  is  true  for  the  numer- 

FiG.  140.— Spherical  Aberration.  OUS    CaseS    of    regular    aStigmatism     in 

The  dotted  lines  are  perpendiculars  to  the  U"    u  r      j.       •  1  'i.  i.   u 

spherical  surface.  which  pcrtect  visual  acuity  cannot  be 

obtained  even  after  correction  with 
cylindrical  lenses — a  combination  of  regular  with  irregular  astig- 
matism. A  very  common  cause  of  irregular  corneal  astigmatism 
is  a  corneal  opacity  (/.  2^/f) ;  an  uncommon  cause  is  keratoconus 

(A  259)- 

Irregular  lenticular  astigmatism  is  produced  by  opacities  or  by 

clefts  in  the  lens,  which  precede  genuine  cataract  (/.  336).     There 

is  no  treatment  for  irregular  lenticular  astigmatism.     Great  optical 

success  has  been  attained  in  correcting  corneal  astigmatism  with 

"  stenopaic  glasses  "  (/.  5/),  that  is,  untransparent  disks  having  a 

small  hole  in  the  middle  for  looking  through.     The  smallness  of 

this  hole  prevents  rays  from  being  received  on  all  but  an  extremely 

limited   corneal   area,  the   curvature   of  which   may  be  considered 

regular ;  the  practical  use  of  stenopaic  glasses  is,  however,  decidedly 

limited  by  the  circumstance  that  such  a  small  hole  admits  of  only 

an  extremely  restricted  visual  field,  and  of  no  excursional  field  at 


ANISOMETROPIA.  38 1 

all !  Roth  tries  to  overcome  this  drawback  by  using  disks — "  sieve 
glasses" — provided  with  numerous  small  holes  of  i.^to  2.2  nnn. 
diameter.  The  visual  field  is  not  narrowed  by  such  a  disk,  but 
only  interrupted  by  unimportant  shadows ;  eye-movements  are  not 
excluded,  since  at  every  change  in  the  position  of  the  eye  another 
hole  lies  in  front  of  the  pupil,  w'hich  may  be  used  directly  to  look 
through. 

3.  ANISOMETROPIA. 

Anisometropia  is  the  term  used  to  indicate  an  inequality  of  the 
refractive  condition  in  the  two  eyes.  It  may  be  present  in  in- 
numerable modifications — as  myopia  and  hyperopia  of  different 
degree,  as  emmetropia  in  one  eye,  myopia  or  hyperopia  in  the 
other,  or  myopia  in  one  eye,  hyperopia  in  the  other.  If  both  eyes 
are  myopic,  but  in  different  degree,  the  right  eye  has  usually  the 
greater  error,  since  even  in  normal  binocular  vision  the  right  eye  is 
used  for  greater  precision  than  is  the  left.^ 

Occasionally  anisometropia  of  the  two  eyes  is  associated  with 
distinct  asymmetry  of  the  orbit,  forehead,  and  face. 

How  does  the  anisometrope  see  ?  There  are  three  possibilities 
to  be  considered  : — 

(/)  He  sees  with  only  one  eye  and  completely  neglects  the  other 
for  both  near  and  far  objects.  This  is  the  case  if  the  visual  acuity 
of  one  eye  is  unusually  better  than  that  of  the  other.  This  may 
generally  be  surmised  from  the  position  of  the  eyes,  since  the  eye 
excluded  from  vision  deviates  outward. 

{2)  The  anisometrope  uses  his  eyes  alternately,  that  with  the 
weaker  refractive  power  being  used  for  distant  objects,  the  other 
with  the  greater  refractive  power  for  near  objects.  In  this  condi- 
tion there  may  be  such  a  correct  position  of  the  eyes  and  such 
good  vision  that  the  patient  himself  is  not  aware  of  any  defect,  or 
is,  on  the  contrary,  rather  proud  of  an  extensive  range  of  accom- 
modation (when  the  eye  with  greater  refractive  power  is  myopic). 

(j)  The  anisometrope  fuses  the  two  retinal  images,  and  has, 
therefore,  binocular  vision  in  the  narrower  sense  of  the  word.  He 
can  do  this,  even  though  the  retinal  images  are  unequally  distinct, 
or  perhaps  even  of  different  size.  If  vision  is  concerned  with  an 
object  lying  within  the  range  of  accommodation  of  both  eyes,  exact 

^  Other  investigators  find  greater  myopia  quite  as  frequently  in  the  left  eye  as  in  the 
right. 


382  ERRORS    OF    REFRACTION. 

dioptric  adjustment  in  both  eyes  may  be  attained  by  accommodat- 
ing unequally  for  each  eye.  The  majority  of  ophthalmologists, 
Bonders  included,  consider  this  impossible.  On  the  other  hand,  a 
minority,  with  v.  Graefe,^  are  of  the  opinion  that  the  association  of 
both  eyes  in  an  exactly  equal  accommodation  may  be  to  a  slight 
degree  dissolved  by  a  natural  or  artificial  difference  in  refraction. 

I  think  that  I  have  offered  a  proof  that  unequal  accommodation  is  possible  within  cer- 
tain limits  and  actually  does  occur  in  anisometropia,  although  my  proof  has  been  attacked 
by  Greeff,  and  particularly  by  Hess.  In  spite  of  that  I  cannot  admit  that  my  view  has 
been  refuted,  and  I  hope  to  be  able  later  to  contradict  the  objections  raised  against  it. 

I  had  a  short  time  ago  a  case  that  seemed  to  me  to  demonstrate  unequal  accommoda- 
tion in  a  manner  quite  free  from  objections.  A  woman  consulted  me  on  account  of 
asthenopic  troubles.  The  shadow-test  disclosed  compound  hyperopic  astigmatism  ;  the 
test  letters  showed  this'  condition  only  in  the  left  eye,  while  the  right  eye  accepted  a 
cylindrical  but  no  spherical  lens.  I  concluded  that  in  the  right  and  more  acute  eye 
there  was  latent  hyperopia,  but  in  the  left  eye  manifest  hyperopia  as  well.  Two  doses 
of  homatropin  proved  that  my  assumption  was  correct,  for  now  not  only  the  left  but  the 
right  eye  also  accepted  a  spherical  lens — on  the  right  a  lens  of  -|-j.o  D.  If  this  clearly 
indicated  unequal  accommodation,  it  became  a  certainty  when  I  had  occasion  eight  days 
later  to  test  the  glasses  prescribed  by  me.  I  examined  the  patient  again  with  the  follow- 
ing result :  while  the  right  eye,  with  a  simple  cylindrical  lens,  was  fixing  letters  {D  = 
^  at  4.  m. ,  the  refractive  condition  of  the  left  eye  was  determined  by  skiascopy  ;  then  the 
test  letters  were  removed,  and  as  the  right  eye  was  gazing  into  space,  the  left  eye  was 
again  tested  by  skiascopy ;  in  both  cases  the  refractive  condition  of  the  left  eye  remained 
the  same,  that  is,  unchanged,  while  the  refractive  condition  of  the  right  eye  had  varied 
to  the  extent  of  j.o  D. 

In  choosing  glasses  we  must  consider  which  of  the  three  possi- 
bilities is  present.  In  (/)  no  attention  need  be  paid  to  the  weaker 
and  neglected  eye,  and  only  the  refractive  error  of  the  better 
eye  need  be  neutralized  by  the  rules  already  given.  In  {2)  some 
cases  need  no  glasses  at  all,  at  least  so  long  as  the  range  of  accom- 
modation is  not  too  small.  If,  for  example,  the  left  eye  is  emme- 
tropic and  the  right  myopic  4.0  D,  and  if  the  eyes  are  used  alter- 
nately, the  patient  can  cover  as  much  ground  with  an  accommoda- 
tive range  oi  4.0  D  as  can  a  normal  pair  of  eyes  with  an  accommo- 
dative range  oiS.o  D,  that  is,  from  co  to  yi  in.  =  12.^  cm.  in  front 
of  the  eye.  If  the  range  of  accommodation  of  this  patient  sinks  to 
2.0  D,  he  will  see  distinctly  with  the  left  eye  from  00  to  ^  ;//.  = 
50  cm.,  and  with  the  right  eye  from  \  m.  to  \  in.,  that  is,  from  2j 
to  //  cm.,  but  between  50  cm.  and  2^  cm.  he  will  not  see  distinctly 
with  either  eye ;   a   convex  lens  of  2.0  D  in   front  of  the  left  eye 

^  Symptomenlehre  der  Augenmuskellahmungen.     Berlin,  1867.     Seite  63. 


AMBLYOPIA    EX    ANOPSIA — HEMERALOPIA.  383 

would  be  of  service  in  this  case.  In  (j)  the  anisometropia  should 
be  totally  neutralized.  If  the  patient  is  young  and  hindered  by  no 
latent  squint,  he  will  grow  accustomed  to  the  glasses  after  a  period 
of  discomfort.  Equally  strong  accommodation  on  both  sides  is 
only  desirable  in  getting  accustomed  to  the  neutralizing  glasses. 
If  the  total  correction  is  not  borne,  a  partial  correction  of  the  aniso- 
metropia must  suffice,  or  the  anisometropia  left  quite  uncorrected. 
I  have  never  had  an  example  of  this  last. 


AMBLYOPIA  AND  AMAUROSIS. 

Dulness  or  weakness  of  vision  and  blindness  are  pathological  signs  with  which  we  are 
often  met.  We  are  accustomed,  however,  to  use  the  terms  amblyopia  and  amaurosis  in 
a  narrower  sense,  also,  for  diseases  whose  anatomical  characteristics  are  either  quite  un- 
known or  at  least  productive  of  no  demonstrable  changes  in  the  eye  itself. 

I.  AMBLYOPIA  WITHOUT  LESION. 
(a)  Amblyopia  ex  Anopsia  [Weaksightedness  from  Disuse). — If 
a  child  hitherto  healthy  begins  to  squint,  he  will  see  double.  To 
obviate  this  distressing  symptom  the  child  learns  by  a  mental  act 
to  suppress  in  the  squinting  eye  the  image  of  the  object  fixed  by  the 
other  eye.  If  this  suppression  is  practised  for  weeks,  months,  or 
years,  there  results  a  permanent  change  in  the  nervous  apparatus 
of  the  visual  organ,  which  is  recognized  as  a  greater  or  less  reduc- 
tion in  visual  acuity,  and  is  called  weaksightedness  from  disuse — 
amblyopia  ex  anopsia. 

It  is  evident  from  the  above  that  weaksightedness  from  disuse  does  not  develop  in 
adults  beginning  to  squint  (from  a  muscular  paralysis,  perhaps);  the  nervous  apparatus 
in  the  latter  case  is  at  complete  maturity,  and  the  suppression  is  therefore  unsuccessful. 
It  is  quite  as  evident  that  weaksightedness  from  disuse  does  not  result  in  children  whose 
eyes  are  prevented  from  seeing  by  some  optical  hindrance  (corneal  opacities  or  cataract) ; 
suppression  is  here  not  called  for ;  the  eyes  rather  seek  to  make  use  of  all  light  pene- 
trating to  the  retina.  If,  on  the  contrary,  an  eye  is  optically  of  little  value,  squint  almost 
always  results  and  there  is  an  associated  amblyopia  of  that  eye. 

The  development  of  amblyopia  may  be  prevented  by  daily  com- 
pelling the  squinting  eye  to  perform  independent  vision,  even  if 
only  for  half  an  hour,  the  other  eye  being  bandaged.  It  must  be 
confessed  that  this  method  soon  becomes  tedious  to  the  patient  and 
the  parents,  but  even  an  amblyopia  already  existing  may  at  times 
be  improved  by  such  exercise  to  the  weak  eye. 

{]))  Henieralopia  {jiigJitblindness,  night-shadows,  pp.  jj  et  scq?) 


384  AMBLYOPIA    AND    AMAUROSIS. 

indicates  a  reduced  sensitiveness  of  the  visual  organ  to  a  weak 
stimulation  of  light.  The  result  of  this  condition  is  such  that  acute- 
ness  of  vision  and  color-sense  begin  to  decline,  or  are  quite  obliter- 
ated in  an  illumination  that  permits  normal  vision  to  a  healthy  eye. 
Nightblindness  is  either  a  symptom,  and  as  such  has  been  already 
mentioned  in  retinitis  pigmentosa,  chororetinitis  syphilitica,  choroid- 
itis, and  prolapse  of  the  retina,  or  it  is  a  disease  of  itself  It  may 
be  congenital,  and  is  then  a  rare  condition  perpetuated  unchanged 
during  life;  it  is,  however,  oftener  acquired  and  may  then  be  cured 
in  a  few  weeks,  this,  as  an  acute  form,  being  distinguished  frorn  the 
chronic,  congenital  condition. 

Nightblindness  may  be  due  to  two  causes : — 

(i)  Overstimulation  (blinding)  to  the  eye. 

(2)  Lack  of  proper  nourishment  to  the  general  body. 

If  both  conditions  occur,  the  disease  is  more  certain  to  show 
itself.  For  example,  "  night-shadows "  are  nearly  endemic  at 
Easter  among  Russians  of  the  lower  class  ;  these  people  are  greatly 
impoverished  by  the  rigor  of  the  northern  winter  and  by  the  severe 
seven  weeks'  religious  fast,  but  they  must  at  that  time  begin  out- 
door work  again  and  thus  expose  themselves  to  the  blinding  rays 
of  the  spring  sun.  Sailors,  after  a  long  cruise,  are  similarly  affected  ; 
the  plain  sea  diet  with  no  fresh  meat  and  vegetables  reduces  the 
bodily  strength  and  leads  probably  to  scorbutus  ;  the  reflection  of 
the  sun's  rays  from  the  sea's  surface  is  dazzling.  Prolonged  marches 
on  plains  of  snow  lit  by  a  bright  sun  (Alpine  tours)  may  cause 
nightblindness.  It  must  be  observed,  however,  that  in  this  "  snow- 
blindness  "  there  is  not  only  hemeralopia,  but  also,  and  principally, 
a  genuine  inflammation  of  the  anterior  segment  of  the  eye — conjunc- 
tiva, cornea,  and  iris — which  is  produced  through  the  ultra-violet 
"  chemical  "  rays  of  the  light  reflected  from  the  snow. 

Since  hemeralopia  is  a  symptom  of  certain  retinal  diseases,  it  may  justly  be  assumed 
that  "  nightblindness  without  lesion  "  is  still  situated  in  the  retina.  The  nature  of  the 
disease  may  be  imagined  as  a  disturbance  of  equilibrium  between  production  and  con- 
sumption of  visual  material. 

Many  ophthalmologists  consider  dazzling  and  poor  nourishment  insufficient  to  cause 
nightblindness.  They  think,  rather,  that  these  conditions  only  incline  a  person  to  sicken, 
but  that  the  essential  cause  of  the  disease  consists  of  a  miasm  (only  suspected,  to  be  sure, 
but  not  yet  demonstrated). 

Treatment  consists — 

(i)  In  withdrawal  from  all  bright  light  by  confinement  in  a  dark- 
ened room  or  by  the  use  of  protecting  glasses. 


COLOR-BLINDNESS NERVOUS    ASTHENOPIA.  385 

(2)  In  improvement  of  the  general  health  by  proper  nourishment, 
fresh  meat,  and  vegetables  ;  if  the  patient  wishes  medicine,  cod-liver 
oil  may  be  prescribed  ;   it  tastes  like  medicine  and  is  a  good  food. 

(c)  Color-blindness  (//.  57  ct  seg.). — There  is  partial  or  com- 
plete color-blindness.  Complete  color-blindness  is  the  inability  to 
distinguish  qualitative  (color)  differences,  the  spectrum  being  rec- 
ognized only  as  light  or  dark.  Partial  color-blindness  is  the  con- 
dition in  which  only  some  of  the  spectrum  waves  are  recognized  as 
specific  (color)  sensations.  By  far  the  most  common  form  of  par- 
tial color-blindness  is  Daltonism,^  or  red  blindness.  The  majority 
of  cases  are  associated  with  green  blindness.  The  red-green  blind 
person,  or  the  one  whose  blindness  alternates — either  red  or  green — 
sees  the  spectrum  in  two  colors,  yellow  and  blue.  What  the  healthy 
person  perceives  as  red,  orange,  yellow,  and  green,  he  perceives  as 
different  shades  of  yellow ;  what  the  healthy  person  perceives  as 
blue-green,  appears  to  the  latter  as  colorless,  the  rest  of  the  spectrum 
being  blue.  In  a  corresponding  way  the  blue-blind  person  is  at 
the  same  time  yellow-blind ;  the  spectrum  is  for  him  composed  of 
only  two  colors,  green  and  red.  Blue-yellow  blindness  is  extraor- 
dinarily rare.  Complete  color-blindness  implies  that  no  colors  at 
all  are  seen  in  the  spectrum,  and  that  the  entire  spectrum  appears 
to  be  composed  of  lines  of  brighter  or  darker  grays.^ 

Color-blindness,  complete  or  partial,  may  be  either  congenital  or 
acquired.  If  acquired,  it  is  a  pathological  sign  that  in  the  majority 
of  cases  is  to  be  referred  to  a  disease  of  the  optic  nerve,  less  fre- 
quently to  disease  of  the  inner  retinal  layers  or  of  the  brain.  Con- 
genital color  blindness  is  a  condition  about  the  cause  of  which 
nothing  is  known.  It  is  commoner  in  men  than  in  women,  and 
has  a  tendency  to  jump  over  a  generation  in  its  inheritance. 

[d)  Nervous  asthenopia  (Wilbrand)  shows  itself  in  many  forms. 
In  school  children  it  causes  complaint  of  haziness,  dimness  of  let- 
ters and  lines,  occasional  double  vision,  blinding  by  lamp  or  even 
daylight,  lacrimation,  pain  in  the  forehead  and  eyes.  In  examina- 
tion we  find  reduction  of  visual  acuity  to  — ,  or  even  — ,  and  con- 

3  7  ' 

centric  narrowmg  of  the  visual  field  growing  more  prominent  as 

1  Dalton,  an  English  physicist,  suffered  from  red  blindness  and  was  the  first  (in  1798) 
to  describe  the  condition  accurately. 

2  An  examination  of  the  various  theories  of  light  and  color  sensations  is  not  within 
the  plan  of  this  book. 

25 


386  AMBLYOPIA    AND    AMAUROSIS. 

the  perimeter  is  used,  a  fact  explainable  as  a  phenomenon  of  ex- 
haustion. This  restriction  is  peculiar  in  that  it  appears  of  varying 
magnitude  according  to  the  size  of  the  test  object  used.  This  ex- 
plains the  fact  that  such  children  are  not  in  the  least  hindered  in 
finding  their  way  about  the  room,  a  condition  that  obviously  must 
be  noticed  in  a  visual  field  absolutely  narrowed,  as  in  atrophy  of  the 
optic  nerve,  for  example.  Color  sense  is  normal  and  the  fundus 
unaffected.  The  examination  of  the  body  in  general  shows  hyper- 
esthesia and  anesthesia  of  the  skin  in  various  localities. 

A  similar  condition  is  found  in  adult  neurasthenics,  but  in  their 
cases  the  complaints  of  eye  pain  and  dazzling  are  more  prominent. 
The  visual  acuity  is  normal ;  narrowing  of  the  field  for  white  and 
often  for  colors  can  be  demonstrated.  In  pronounced  hysteria  ^  the 
condition  is  very  marked ;  Kopiopia  hysterica  is  the  name  given  to 
it.  Besides  pain,  dazzling,  reduction  of  visual  acuity,  and  narrow- 
ing of  the  visual  field,  usually  in  one  eye,  there  may  be  spasm  of 
the  lid,  weakness  of  the  ciliary  muscle,  eye-muscles,  and  of  the 
levator ;  greater  disturbance  of  color  sense,  and,  finally,  a  host 
of  sensible  and  motor  paralyses  and  pareses  in  all  regions  of  the 
body. 

Before  the  diagnosis  of  nervous  asthenopia  is  made  from  the 
foregoing  subjective  symptoms,  we  must  see  whether  the  patho- 
logical condition  does  not  depend  upon  some  refractive  error,  such 
as  hyperopia  or  astigmatism,  or  upon  some  conjunctival  trouble  or 
weakness  of  the  internal  recti.  The  ophthalmoscopic  evidence  also 
must  be  negative.^ 

In  cases  where  there  is  a  doubt  whether  reduced  vision  with 
concentric  narrowing  of  the  field  and  disturbance  of  color-sense  is 
due  to  hysteria  or  to  a  deep  lesion  of  the  optic  nerve,  the  further 
course  of  the  disease  will  explain  matters;  optic-nerve  atrophy 
leads  continuously  to  the  bad ;  hysterical  amblyopia,  on  the  other 
hand,  arises  suddenly,  remains  for  some  time  unchanged,  and  dis- 
appears as  suddenly  as  it  arose. 

Opinions  differ  as  to  the  localization  of  the  disturbances.  Knies  thinks  that  they  are 
peripheral,  about  at  the  place  where  the  nerves  pass  through  narrow,  bony  canals  and  are 

^  From  ij  varipa,  the  uterus.  It  was  once  the  belief  that  the  chameleon-like  disease 
called  hysteria  was  seen  only  in  women  and  had  its  origin  in  the  uterus.  It  is  now  known 
that  men,  too,  are  similarly  affected. 

2  Bernhardt  finds  that  in  many  cases  of  nervous  asthenopia  there  is  really  a  slight 
paleness  of  the  temporal  half  of  the  optic  disc. 


SIMULATION,    MALINGERING.  387 

0. 

easily  compressed  by  dilatation  of  the  blood-vessels.      Most  authorities  think  that  they 
are  central,  that  is,  located  in  the  cerebral  cortex. 

There  is  a  particular  tendency  to  such  diseased  conditions  among 
hereditary  sufferers — persons  whose  parents  have  been  victims  of 
nervous  diseases.  As  immediate  causes  may  be  named  over-exer- 
tion at  school  or  in  the  struggle  for  existence,  injuries  (traumatic 
neuroses),  often  of  a  trifling  nature,  and  diseases  of  the  female  geni- 
tal organs  (Kopiopia  hysterica). 

Treatment  must  be  chiefly — 

(i)  Relief  to  the  eyes  by  rest  from  work  and  by  the  use  of  dark 
glasses ;  these  may  even  restore  normal  vision  for  a  moment ;  it 
may  then  be  assumed  that  the  reduced  visual  acuity  was  due  to 
dazzling. 

(2)  Improvement  in  physique  by  wet  dressings,  massage,  open- 
air  exercise,  and  good  food. 

(3)  By  suggestion  in  the  form  of  simple  medicines  and  metallo- 
and  electro-therapy. 


APPENDIX. 

Simulation,  Malingering. — It  occasionally  happens  that  a  per- 
son declares  that  he  is  blind  or  weaksighted  in  one  eye;  if  this  eye 
is  normal,  we  speak  of  simulation  ;  if  the  eye  is  really  ambylopic 
and  the  symptoms  merely  exaggerated,  we  speak  of  aggravation. 
Simulation  and  aggravation  are  not  really  diseases,  but  as  the  oph- 
thalmologist is  often  concerned  with  them,  they  must  be  briefly 
considered. 

Simulants  (malingerers)  state  as  a  rule  that  only  one  eye  is  weak  or 
blind,  since  it  is  easier  to  play  that  part  than  it  is  to  pretend  to  be 
weaksighted  or  blind  in  both  eyes.  Their  reason  for  simulation  is 
the  wish  to  escape  military  service  or  to  get  damages  on  account 
of  an  injury  from  some  corporation  or  insurance  company;  other 
simulants,  particularly  hysterical  women,  have  only  the  impulse  to 
make  themselves  interesting.  In  some  cases,  especially  in  chil- 
dren, no  rational  cause  can  be  discovered. 

The  physician's  task  is  to  unmask  the  simulant.  Many  ingen- 
ious devices  have  been  used,  all  depending  upon  the  fact  that  the 
normal  individual  does  not,  in  his  visual  perceptions,  take  into 
account  whether  they  come  from  his  right  or  from  his  left  eye,  or 
from  both.     For  example,  if  a  pencil  is  held  between  a  book  and 


388  APPENDIX. 


V 


the  eyes,  the  pencil  does  not  obscure  the  same  word  or  part  of  it 
from  the  right  eye  as  it  does  from  the  left ;  reading  can  go  on,  then, 
uninterruptedly,  the  reader  being  unconscious  of  which  word  is 
seen  by  the  right  eye  alone,  which  by  the  left  alone,  and  which  by 
both  eyes  together.  An  individual  who  claims  to  be  blind  or  weak- 
sighted  in  one  eye,  is  proved  to  be  simulating  if  he  can  read  unin- 
terruptedly under  the  condition  just  given.  The  size  of  the  type 
read  is  at  the  same  time  a  test  of  the  visual  acuity  of  the  eye 
assumed  to  be  blind  or  amblyopic. 

Another  trap — place  before  the  eye  asserted  to  be  normal  a  strong 
convex  lens,  say  of  lo.o  D.  Assuming  it  to  be  emmetropic,  it 
can  then  read  fine  type  at  -^  in.  from  the  lens  at  the  most.  Now, 
appearing  to  pay  no  attention  to  the  eye  asserted  to  be  blind  or 
weak,  the  test-type  is  gradually  removed  beyond  the  focal  distance 
of  the  convex  lens.  If  the  person  is  still  able  to  read  in  spite  of 
this,  it  is  evident  that  he  reads  with  the  blind  or  amblyopic  eye  ! 

A  third  method  depends  upon  the  production  of  double  images 
by  prisms,  for  which  certain  precautionary  measures  must  be 
adopted.  Simulants  suppose  that  the  acknowledgment  of  double 
images  is  equivalent  to  the  confession  of  binocular  vision ;  they 
therefore  persistently  deny  double  images.  It  consequently  be- 
comes necessary  to  convince  the  person  examined  that  he  can 
see  double  with  only  one  eye.  For  this  purpose  the  eye  asserted 
to  be  blind  is  covered,  and  in  front  of  the  other  eye  there  is  placed 
a  prism  so  adjusted  that  it  covers  only  one-half  the  pupil,  the  other 
half  being  left  uncovered.  Any  object  fixed  will  now  appear 
double,  since  rays  refracted  by  the  prisma  produce  one  retinal 
image  lying  beside  the  image  produced  by  the  rays  entering  the 
pupil  directly.  After  the  person  has  acknowledged  the  double 
images  and  described  their  location,  the  cover  of  the  (asserted) 
blind  eye  is  as  if  by  chance  withdrawn,  the  prisma  being  at  the 
same  time  advanced  so  that  it  now  covers  the  entire  pupil  of  the 
sound  eye.  If  the  person  now  acknowledges  the  appearance  of 
double  images,  it  is  a  proof  that  he  can  see  with  each  eye. 

Still  another  method  depends  on  the  fact  that  colored  letters  on 
a  dark  ground  cannot  be  seen  through  glasses  of  the  complement- 
ary colors, — green-blue  letters,  for  example,  are  invisible  if  looked 
at  through  red  glasses,  because  the  green-blue  rays  proceeding 
from  the  letters  are  not  transmitted  through  the  red  glass.  If  now 
green-blue  test  letters  on  a  dark  ground  are  offered  to  the  person 


INTOXICATIONS — AMBLYOPIA.  389 

for  reading  while  he  wears  a  green  glass  over  the  (asserted)  blind 
eye  and  a  red  glass  over  the  sound  eye,  the  sound  eye  will  be  pre- 
vented from  seeing  the  letters,  and  if  the  person  says  he  recognizes 
and  reads  the  letters  under  these  circumstances,  it  can  be  done 
only  by  the  (asserted)  blind  eye  !  The  size  of  the  letters  read  is  at 
the  same  time  a  test  of  the  visual  acuity. 

2.  INTOXICATIONS. 

(a)  Uremic  Amaurosis. — In  many  diseases  of  the  kidneys, 
particularly  in  scarlet  fever  nephritis  and  in  the  nephritis  of  preg- 
nant and  puerperal  women,  uremia  may  result,  a  pathological 
condition  dependent  upon  supersaturation  of  the  blood  with  urinary 
ingredients.  Uremia  shows  itself  in  mild  cases  by  headache,  dul- 
ness,  oppression,  nausea,  and  vomiting,  and  by  twitchings  and 
tonic  contractions  of  the  face  and  limbs  ;  in  severe  cases  there  are 
also  spasms  and  coma.  An  occasional  result  of  uremia  is  uremic 
amaurosis,  that  is,  total  blindness  of  both  eyes,  appearing  some- 
times suddenly,  sometimes  after  a  day  or  so  of  diminished  visual 
acuity.  Blindness  may  be  so  complete  that  light  cannot  be  dis- 
tinguished from  dark,  or  even  that  the  pupils  no  longer  react  to 
light  stimulation.  If  the  patient  survives  an  attack  of  uremia,  the 
blindness  may  completely  disappear  in  a  few  days.  Since  the 
ophthalmoscopic  examination  shows  a  normal  fundus,  this  amau- 
rosis depends  obviously  upon  some  disturbance  in  the  brain.  In 
cases  (rare,  indeed)  where  even  the  pupillary  reflex  is  lost,  we  must 
assume  that  not  only  is  the  center  for  optical  perception,  but  also  the 
region  of  the  corpora  quadrigemina,  in  which  lies  the  center  for 
reflex  pupillary  action  (/v^.  iij,  p.  joj),  diseased. 

{d)  Diabetic  Amblyopia. — The  numerous  diseases  of  the  eyes 
resulting  from  diabetes  include  also  an  amaurosis  without  lesion. 
This  may  lead  the  patient  to  the  physician  before  the  usual  symp- 
toms— loss  of  flesh,  muscular  weakness,  great  hunger  and  thirst, 
increased  excretion  of  urine — have  made  it  clear  that  there  is  a 
deep-seated  disease.  Nothing  positive  is  known  of  the  cause  of 
diabetic  amaurosis,  but  small  hemorrhages  or  fatty  degeneration  in 
the  optic  nerve  have  been  suspected. 

{c)  Blindness  from  Malarial  Fever  and  Quinin. — Cases  of 
malarial  fever  have  been  reported  in  which  bilateral  blindness  oc- 
curred every  time  at  the  beginning  of  the  febrile  attack,  and  disap- 
peared with  the  critical  sweat,  after  six  to  eight  hours.     The  remedy 


390  APPENDIX. 

for  malaria,  quinin,  proved  itself  to  be  effective  against  this  ambly- 
opia also.  Strange  to  say,  other  cases  have  been  reported  in  which 
large  doses  of  quinin  have  produced  bilateral  amblyopia.  An 
analogous  effect  of  quinin  upon  the  auditory  apparatus  is  a  well- 
known  phenomenon,  a  small  dose,  even  one  gram,  being  enough 
to  produce  ringing  in  the  ears  and  deafness.  A  reduction  of  visual 
acuity  by  quinin  (quinin  amblyopia)  is  not  uncommon.  In  rare 
cases  this  amblyopia  may  go  on  to  complete  blindness.  The 
retinal  vessels  are  then  seen  to  be  narrow,  the  discs  pale.  It  may 
be  assumed  that  quinin  amaurosis  depends  upon  ischemia  of  the 
retina. 

3.  WEAKSIGHTEDNESS  AS  A  SIGN  OF  CEREBRAL  DISEASE. 
{a)  Hemianopsia. — Semi-blindness  denotes  the  obliteration   of 
half  the  visual  field  in  both  eyes,  arising  from  a  localized  cause 
common  for  both  eyes.     If  this  obliterated  half  of  the  field  is  the 


Fig.  141. — Homonymous  Hemianopsia,  Resulting  from  Unilateral  Cerebral  Hemorrhage. 
The  darkened  areas  indicate  the  obliterations.     The  normal  areas  remaining  are  contracted. 

same  in  both  eyes,  for  example,  that  half  of  the  field  to  the  right 
of  both  eyes,  we  speak  of  homonymous  hemianopsia.  This  occurs 
most  commonly  in  a  lateral  half  of  the  field,  rarely  in  the  upper  or 
lower  half  of  the  field.  The  line  of  separation  between  the  normal 
and  the  obliterated  halves  of  the  field  in  lateral  homonymous 
hemianopsia  runs  perpendicularly  through  the  fixation  point;  in 
many  cases,  however,  it  passes  to  the  side  of  this  point,  so  that  the 
normal  portion  of  the  visual  field  extends  2°,  5°,  or  even  10°  into 
the  territory  of  affected  area.  This  area  is  called  the  "  atypical 
field  "  (Mg:  141). 

The  anatomical  reasons  for  this  atypical  field  are  still  under  dispute.     Wilbrand  ad- 
vances the  view  that  fibers  from  both  optic  tracts  supply  the  central  retinal  area.     Foer- 


HEMIANOPSIA.  39I 

ster  has  described  a  case  of  bilateral  homonymous  hemianopsia  in  which  complete  blind- 
ness did  not  occur,  as  naturally  would  at  one  time  have  been  assumed,  but  there  remained 
a  small  central  field  with  retention  of  good  visual  acuity  (about  ■^).  Foerster,  therefore, 
repudiates  the  theory  of  a  sujjply  to  the  retina  from  both  tracts,  and  concludes  that  that 
part  of  the  cerebral  cortex  connected  with  the  center  of  the  retina  is  more  luxuriantly 
supplied  with  blood-vessels  than  is  the  rest  of  the  cortex,  and  that,  therefore,  in  spite  of 
thrombosis  of  the  principal  vessels,  such  a  part  of  the  cortex  would  still  be  nourished  with 
blood.  Finally,  v.  Monakow,  who  disputes  the  theory  that  certain  areas  of  the  retina 
are  exclusively  associated  with  certain  areas  of  the  cortex,  or  considers  such  a  theory 
at  least  unproven  and  improbable,  explains  the  escajDC  of  the  central  area  of  the  retina  by 
the  assumption  that  it  is  in  association  with  a  much  larger  part  of  the  cortex  than  is  any 
other  area  of  the  retina. 

Visual  acuity,  color  sense,  and  the  edges  of  the  field  of  the  reti- 
nal halves  still  functionating,  may  all  be  normal.  There  is,  to  be 
sure,  a  gradual  contraction  of  the  field  still  remaining.  A  right- 
sided  hemianopsia  causes  more  disturbance  than  does  a  left-sided 
one,  because  we  read  and  write  from  left  to  right.  The  ophthal- 
moscopic examination  is  normal. 

If  both  obliterated  halves  of  the  visual  field  are  at  the  temporal  side  of  the  fixation 
point,  that  is,  one  to  the  left  side  and  one  to  the  right,  the  condition  is  spoken  of  as 
"  temporal  hemianopsia.''  A  "  nasal  hemianopsia  "  is  perhaps  possible,  but  no  such  case 
has  been  described  which  might  not  liav'e  another  significance.  It  must  be  supposed  that 
disease  of  the  retinse  and  optic  nerves  can  produce  all  possible  forms  of  restrictions  in  the 
visual  fields,  but  according  to  the  definition  given  above  (/.  jgo)  they  are  not  to  be  con- 
sidered hemianopic  in  their  nature. 

The  reason  for  hemianopsia  will  be  seen  by  examining  iv^i'.  112 
and  irj  {/'/'■  jo.^,  joj).  If  the  right  optical  tract  or  its  connec- 
tions with  the  cerebral  cortex  are  interrupted,  or  if  the  center  for 
optical  perception  (cortex  of  the  occipital  lobe)  becomes  incapable 
of  functionating,  a  left-sided  hemianopsia  must  result,  and  vice 
versa.  Temporal  hemianopsia  is  obviously  produced  by  a  lesion 
at  that  part  of  the  chiasm  where  the  decussating  fibers  of  both 
tracts  are  interwoven.  Since  the  fibers  that  do  not  decussate  are 
never  in  contact  with  each  other,  it  is  scarcely  possible  that  the 
same  single  lesion  can  affect  both  bundles  of  fibers  and  destroy 
their  function  of  caring  for  the  temporal  halves  of  the  retinae  (nasal 
halves  of  the  visual  field)  at  the  same  time. 

As  anatomical  causes  of  hemianopsia  have  been  found  cerebral 
hemorrhages,  emboli,  injuries  and  tumors,  seated  partly  in  the  cor- 
tex, partly  at  the  base  of  the  brain. 

The  clinical  significance  of  hemianopsia  is  of  pathological  import, 
since,  taken  with  other  signs  (hemiplegia,  aphasia,  hemianesthesia),  it 
may  be  used  for  the  localization  of  a  brain  lesion. 


392  GLAUCOMA. 

{b)  Amaurosis  partialis  fugax,  transient  hemianopsia,  may  occur 
as  an  attack  of  blindness  lasting  usually  no  more  than  fifteen  or 
twenty-five  minutes.  The  attack  begins  with  the  phenomenon  of  a 
dark  spot  at  the  same  place  (homonymous)  in  both  eyes.  This 
scotoma  spreads  centrifugally  but  remains  confined  to  the  temporal 
half  of  one  visual  field  and  the  nasal  half  of  the  other.  Flickering 
shadows  are  now  seen,  which  move  about  in  a  zigzag  manner 
{teichopsia),  while  the  edge  of  the  dark  spot  expands  toward  the 
edge  of  the  visual  field.  The  flickering  finally  ceases  and  the  dark 
spot  disappears. 

The  disease  must  be  seated  in  the  brain  cortex.  It  is  often  asso- 
ciated with  unilateral  headache  (migraine),  vertigo,  malaise,  disturb- 
ances of  speech  and  of  memory,  and  other  like  irregularities  refer- 
able only  to  the  brain.  It  may  be  assumed  that  the  symptoms  are 
due  to  arterial  spasm,  and  that  the  flicker  scotomata,  malaise,  and 
vertigo  refer  to  such  a  spasm  in  the  cortex,  the  unilateral  headache 
to  spasm  in  the  dura  mater. 

The  first  attack  distresses  the  patient  very  much,  but  he  soon 
convinces  himself  of  the  harmlessness  of  the  symptom.  Treatment 
must  consist  of  regulation  of  the  daily  life  and  restriction  in  mental 
exercise.     Quinin  and  bromid  of  potassium  have  been  advised. 


GLAUCOMA. 

I.  INTRODUCTION. 
Glaucoma^  is  applied  to  a  disease  still  obscure  in  many  respects, 
but  characterised  by  the  essential  sign  o{  increase  in  intraocular  pres- 
sure. This  does  not  imply  that  every  eye  with  increased  tension  is 
glaucomatous,  or  that  an  eye  is  not  glaucomatous  because  at  a  par- 
ticular instant  the  tension  is  normal.  The  interpretation  is  rather 
the  following  :  nearly  all  pathological  signs  of  glaucoma  are  directly 
or  indirectly  the  results  of  increased  tension,  but  the  cause  of  this 
tension  modifies  the  diagnosis  and  is  still  the  starting  point  for  all 
theories  of  glaucoma.     These  theories  agree  in  only  one  particular, 

1  The  name  refers  to  the  greenish  discoloration  of  the  pupil ;  although  the  same 
appearance  is  commonly  seen  in  old  and  healthy  eyes,  if  only  the  pupil  is  dilated  enough. 
The  discoloration  is,  therefore,  suggestive  of  glaucoma  only  in  cases  where  the  pupil  is 
dilated,  as  it  is  in  glaucomatous  eyes,  whereas  old  persons  usually  have  contracted  pupils. 


INTRODUCTION.  393 

namely,  that  increased  tension  depends  upon  increase  in  contents 
within  the  eye.  The  deeper  question  as  to  the  cause  of  this  increase 
in  contents  is,  even  to-day,  an  unfailing  source  of  scientific  battle. 

On  the  other  hand,  there  is  general  unanimity  concerning  the 
changes  in  the  eye  which  may  be  considered  as  resulting  from  this 
increased  tension.  These  changes  appear  in  different  forms,  accord- 
ing as  the  increase  in  tension  is  rapid  or  slow ;  in  the  latter  case  the 
consequences  are  less  conspicuous,  because  the  eye  has  time  to 
accommodate  itself  to  the  altered  relations  of  tension. 

(a)  Let  us  assume  that  there  takes  place  a  rapid  increase  of  ten- 
sion resulting  from  increase  in  vitreous  in  an  eye  quite  healthy  up 
to  that  time.  The  immediate  consequence  will  be  that  the  lens  is 
pressed  forward  and  the  zonule  of  Zinn  stretched.  The  advance  of 
the  lens  is  shown  by  shalloivness  of  the  anterior  chamber  ;  the  stretch- 
ing of  the  zonule  of  Zinn  by  reduction  in  range  of  accommodation, 
the  contraction  of  the  ciliary  muscle  being  now  unable  to  relax  the 
suspensory  ligament  completely.^  A  further  consequence  is  a 
profound  change  in  the  circulation  in  the  eye.  The  blood  passes 
into  the  retinal  vessels  only  during  the  systole  of  the  heart,  while 
at  the  moment  of  diastole  the  eye's  internal  pressure  overcomes  the 
blood  pressure  and  the  arterial  walls  are  squeezed  together.  For 
this  reason  an  arterial  pulse  in  the  retina  becomes  visible  with  the 
ophthalmoscope.  Tlie  retinal  veins  are  tortuous  and  swollen  in  con- 
sequence of  the  compression  on  the  spot  where  the  vein  bends  at 
right  angles  in  passing  from  the  retina  into  the  optic  nerve.  In  the 
same  way  the  venae  vorticosae  are  squeezed  by  the  pressure  within 
the  eye  just  where  they  pierce  the  sclera  obliquely.  The  result  is 
that  an  abnormal  amount  of  blood  is  discharged  from  the  eye 
through  the  anterior  ciliary  veins  and  they  become  therefore  dilated 
and  tortuous.  A  third  consequence  is  a  cloudiness  of  the  cornea. 
Pressure  opacity  may  be  produced  at  any  time  in  the  eye  of  a 
cadaver  or  of  an  animal  ;  it  might  be  supposed,  therefore,  that  the 
opacity  of  glaucoma  was  a  purely  mechanical  pressure  opacity 
explainable  by  unequal  stretching  of  the  corneal  fibrils ;  but  the 
matter  is  not  so  simple  (compare  p.  2jj),  since  pressure  opacity 
disappears  as  soon  as  the  pressure  is  removed,  while  glaucoma 
opacity  disappears   only  by  degrees.      Nor    is  the  cornea  alone 


1  Knies  explains  the  reduction  in  range  of  accommodation  to  be  due  to  round-cell  infil- 
tnition  into  the  ciliary  muscle. 


394  GLAUCOMA. 

cloudy,  the  aqueous,  perhaps  even  the  vitreous,  showing  the  same 
condition. 

Further  results  of  rapid  increase  in  pressure  impress  the  ciliary 
nerves  in  the  form  of  pain  radiating  toward  the  forehead  and  upon 
the  face  (ciliary  neuralgia),  and  the  nerve  fibers  supplying  the 
sphincter  pupillae  and  cornea  (paralysis).  A  paralysis  of  the 
sphincter  makes  the  pupil  large  and  immovable  (iridoplegia),  and 
paralysis  of  corneal  nerves  makes  the  cornea  insensitive. 

Finally,  a  result  of  rapid  increase  in  tension  may  show  itself  as 
inflammation.  A  purely  mechanical  explanation  of  this  fact  is  quite 
impossible.  The  inflammation  is  evidenced  by  lacrimation,  redness, 
and  swelling  of  the  conjunctiva  and  lids,  by  cloudiness  of  the  aque- 
ous (and  vitreous?),  and  by  discoloration  of  the  iris  ;  even  posterior 
adhesions  have  been  observed.  The  corneal  opacities  and  the  pain 
may,  of  course,  be  ascribed  to  the  inflammation  itself  (/>.  402). 

It  is  obvious  that  these  changes  must  severely  disturb  the  visual 
acuity,  which,  with  a  cloudy  cornea,  may  sink  even  to  the  mere 
ability  to  count  fingers.  If  this  reduction  in  vision  depends  solely 
upon  opacity  of  the  refractive  media,  the  field  of  vision  will  be  of 
normal  extent;  but  if  retina  and  optic  nerve  are  injured  by  inter- 
ruption to  the  blood  current,  there  will  be,  besides  a  reduction  in 
visual  acuity,  a  distinct  contraction  of  the  visual  field.  If  the  in- 
creased tension  is  very  decided,  retina  and  optic  nerve  refuse  al- 
together to  functionate,  the  eye  cannot  even  distinguish  light  from 
darkness,  and  is  therefore  amaurotic. 

ip)  Let  us  assume  another  case,  in  which,  by  increase  in  the 
vitreous,  an  increase  in  internal  pressure  results  very  gradually. 
There  is  no  sign  of  inflammation,  pain  only  slightly  or  not  at  all 
complained  of;  but  the  anterior  ciliary  vessels  are  dilated  and  tortu- 
ous, the  anterior  chamber  is  shallow,  the  pupil  moderately  dilated, 
and  the  iris  sluggish  in  movement.  In  addition,  there  is  one  more 
sign  that  is  of  the  greatest  diagnostic  importance — tlie  excavation  of 
the  optic-nerve  sheath.  This  sheath  is  the  portion  of  the  fundus 
offering  the  least  resistance,  and  has  been  softened,  perhaps,  by  some 
inflammatory  process  (/.  402).  As  a  consequence  of  continued 
increase  in  pressure,  the  nerve  gives  way,  and  in  time  an  excava- 
tion is  produced.  Hand-in-hand  with  the  crowding  of  the  optic 
nerve  backward  there  is  atropliy  of  the  ncr-ve  fibers.  The  result  is 
that  the  field  of  vision  becomes  contracted,  and  the  acuity  of  vision 
declines  till  total  blindness  is  the  final  outcome. 


GLAUCOMA    ACUTUM.  395 

Glaucoma  as  an  idiopathic  disease  usually  attacks  persons  of  fifty 
or  beyond,  although  younger  persons  are  not  altogether  out  of  dan- 
ger; a  case  of  glaucoma  has  been  reported  in  a  five-year-old  boy. 
Hyperopes  are  more '  disposed  to  glaucoma  than  emmetropes ; 
myopes  are  least  affected  ;  a  particular  predisposition  is  found  in 
those  who  suffer  from  trigeminal  neuralgia.  Both  eyes  are  at- 
tacked, as  a  rule,  although  not  necessarily  at  the  same  time;  the 
interval  between  the  disease  in  the  first  eye  and  that  in  the  second 
may  be  only  a  few  hours,  or  it  may  be  twenty  years. 


2.  VARIETIES  OF  GLAUCOMA. 

A.  PRIMARY  GLAUCOMA. 

Glaucoma  is  called  primary  if  it  occurs  in  an  eye  previously 
healthy ;   secondary,  if  in  an  eye  already  affected  by  some  disease. 

(a)  Glaucoma  Acutum  {^Inflaniniahn'y  Glaucovia). — Prodromal 
syniptovis  usually  precede  an  attack  of  idiopathic  glaucoma.  They 
consist  of  moderate  pain  in  the  eye  and  its  surroundings,  haziness 
or  actual  cloudiness  of  the  visual  field,  and  the  appearance  of  col- 
ored rings  about  flames  of  light,  this  last  being  a  phenomenon  of 
diffraction  due  to  a  moderately  diffused  corneal  opacity.^ 

If  occasion  offers  to  examine  an  eye  during  such  a  prodromal 
stage,  it  is  found  to  be  of  moderately  increased  tension ;  the  con- 
junctiva is  hyperemic,  the  cornea  soft  and  delicately  "smoky,"  the 
aqueous  similarly  cloudy,  the  pupil  moderately  dilated — in  short, 
all  the  consequences  just  described  of  rapid  increase  in  tension  of 
moderate  degree.  Such  symptoms  appear  at  intervals,  and  each 
attack  may  subside  without  injuring  the  eye.  It  may  be  repeated 
for  weeks,  months,  or  even  years,  but  finally  a  severe  attack  occurs, 
which  is  the  fully  developed  glaucoma,  glaucovia  evohitiun. 

A  developed  glaucoma  is  easy  to  recognize  during  an  attack. 
The  association  of  inflammation  and  dilated  pupil  is  seen  in  no  other 
disease  of  the  eye,"  while  it  may  be  noted  that  the  redness  of  glau- 

'  Colored  rings  around  flames  are  seen  by  any  person  whose  corneal  surface  is  smeared 
over  by  a  finely  diffused  conjunctival  secretion  (see  /.  jS6). 

*  Of  course,  it  is  assumed  that  the  dilatation  of  the  pupil  is  not  the  effect  of  atropin. 
The  very  first  question  addressed  to  any  patient  with  an  inflamed  eye  and  dilated  pupil 
must,  therefore,  always  be  whether  he  has  not  already  been  treated  by  a  physician. 


396  GLAUCOMA. 

comatous  inflammation  has  its  own  peculiar  somberness.  If  there 
is  also  an  increase  in  tension,  the  presence  of  glaucoma  can  no 
longer  be  in  doubt. 

In  spite  of  all  this  an  attack  of  acute  glaucoma  is  at  times  mistaken.  It  may  happen 
that  intense  headache,  fever,  and  vomiting  takes  away  any  suspicion  that  the  eye  is  in- 
volved, and  leads  to  the  diagnosis  of  some  general  systemic  disease.  Confusion  with 
serous  iridocyclitis  is  also  possible,  since  in  the  latter  the  pupil  is  dilated,  though  not  so 
noticeably  as  in  glaucoma,  and  the  tension  is  increased ;  but  in  serous  iridocyclitis  the 
anterior  chamber  is  deep  ;  in  glaucoma,  on  the  contrary,  it  is  shallow.  Moreover,  the 
deposits  on  the  posterior  surface  of  the  cornea,  which  are  so  unusually  characteristic  of 
serous  iridocyclitis,  are  never,  or  only  in  the  most  insignificant  degree,  present  in 
glaucoma. 

The  course  of  the  disease  may  vary  considerably.  In  the  worst, 
and,  fortunately,  the  rare  cases,  the  result  of  the  first  attack  maybe, 
within  a  few  hours,  total  and  incurable  blindness — glaucoma  fulmi- 
nans.  The  rule  is  that  the  storm  breaks  after  days  or  weeks  of 
severe  pain,  but  leaves  behind  it  a  permanent  increase  of  tension 
with  all  its  dire  consequences.  This  is  shown  in  excavation  of  the 
disc,  reduction  in  visual  acuity,  and  contraction  of  the  visual  field. 
After  a  time  a  new  attack  occurs,  producing  further  impairment, 
until  finally  the  eye  becomes  of  stony  hardness  and  totally  blind ; 
this  condition  in  progressive  glaucoma  is  called  glaucoma  absolutwn. 
The  pathological  storm  may  not  calm  down,  the  eye  may  remain 
somewhat  inflamed  and,  of  course,  with  increased  tension,  and  this 
condition  is  called  chronic  inflammatory  glaucoma. 

{b)  Glaucoma  Simplex  (^Simple  Glaucoma). — The  essence  of  sim- 
ple glaucoma,  also,  is  increase  in  tension,  but  this  increase  develops 
so  slowly  that  the  patient  fails  to  notice  its  consequences.  Gradu- 
ally, however,  after  these  consequences  have  made  a  lasting  im- 
pression, the  patient  notices  some  impairment  in  vision.  An  ex- 
amination by  the  surgeon  at  this  time  shows  reduction  in  visual 
acuity  and  contraction  of  the  visual  field,  more  or  less  marked  as 
the  disease  has  been  of  longer  or  shorter  duration.  The  form  of 
the  visual  field  is  somewhat  peculiar ;  that  is  to  say,  it  is  contracted 
with  preponderant  involvement  of  the  nasal  half  {Fig.  1^2,  a,  left 
visual  field').  As  the  disease  progresses  the  visual  field  contracts 
more  and  more,  so  that  finally  there  remains  only  a  segment  on  the 
temporal  side  {Fig.  14.2,  b,  right  visual  field). 

The  objective  examination  shows  that  the  visual  disturbances 
are  not  due  to  changes  in  the  refractive  media,  but  depend  upon 
the  excavation  within  the  optic  nerve  sheath  and  upon  the  asso- 
ciated atrophy  of  the  nerve  fibers. 


GLAUCOMA    SIMPLEX. 


w 


There  are  three  varieties  of  excavation  of  the  disc,  a  physiological,  an  atrophic,  and  a 
glaucomatous.  The  physiological  {Fig.  i^j)  is  always  bilateral,  includes  only  a  part  of 
the  surface  of  the  disc,  and  is  to  be  considered  an  exaggeration  of  the  physiological  cup 
yFig.  14J)  from  which  the  retinal  vessels  spring  into  view  ;  these  vessels  must,  therefore, 
pass  over  part  of  the  papilla  on  a  level  with  the  retina  before  they  reach  the  retina  itself 


Fig.  142. — Visual  Fields  in  Simple  Glaucoma. 
The  darkened  areas  denote  the  obliterated  portions  of  the  fields. 

{Fig.  I4S)-  In  atrophic  and  glaucomatous  excavation  the  condition  is  quite  different ! 
In  both,  the  entire  nerve  sheath  '  is  pushed  back  from  the  plane  of  the  retina  ;  in  the 
atrophic  variety  no  further  than  the  lamina  cribrosa,  that  is,  about  as  far  as  the  thick- 
ness of  retina  and  choroid ;  but  in  the  glaucomatous  variety  {Fig.  144)  very  much  far- 
ther, since  the  lamina  cribrosa  itself  is  carried  backward  by  the  pressure.     Consequently, 


f /;,//:'/,/ 


/  ■.>//y/'ffw/iff(Miis 
spitftr. 

Fig.  143. — Physiological  Excavation.     {After  Pagenstecher  and  Genth.) 

The  excavation  is  about  one-third  as  broad  as  the  optic  nerve.     Just  below  the  excavation  are  seen 

cross-sections  of  two  blood-vessels. 


the  blood-vessels  at  the  edge  of  the  disc  appear  in  glaucomatous  excavation  as  if  broken 
oK  {Fig  146),  and  in  atrophic  excavation  only  moderately  bent  over  or,  perhaps,  not  at 
all  modified. 


'  Schweigger  declares  that  pressure  excavation  may  include  only  a  part  of  the  surface 
of  the  disc.  The  distinction  between  this  and  physiological  excavation  would,  in  such  a 
case,  be  impossible  by  mere  examination.  Other  factors  would  have  to  be  considered, 
above  all,  the  functionating  powers  of  the  eye  ;  normal  visual  acuity  and  normal  visual 
field  would  exclude  pressure  excavation  with  certainty.  Again,  the  disc  of  the  other 
(healthy)  eye  must  be  used  for  comparison.  If  this  disc  is  flat,  an  excavation  in  the 
diseased  eye,  even  if  only  partial,  would  indicate  a  glaucomatous  origin. 


398 


GLAUCOMA. 


The  degree  of  excavation  can  be  estimated  by  the  help  of  parallax  (/.  ij^s'),  or  meas- 
ured by  determining  the  refraction  at  the  edge  of  the  disc  on  the  one  hand,  and  at  the  base 
of  the  excavation  on  the  other.  In  pressure  excavation  there  is  often  to  be  seen  a  "  halo 
glaucomatosus,"  that  is,  a  yellowish-white  ring  surrounding  the  disc,  ophthalmoscopic 
evidence  of  the  obliterated  choroidal  ring  {Fig.  146).  Excavations  cannot  with  cer- 
tainty be  distinguished  by  their  color,  for  in  all  three  varieties  the  excavated  portion  is 
white  and  dotted  over  with  fine  points,  due  to  the  shimmer  of  the  lamina  cribrosa.     In 


Fig.  144. — Glaucomatous  Optic-Nerve  Excavation.     (A/ter  Pagenstecher  and  Genth) 

physiological  excavation,  however,  the  lai^er  and  not  excavated  portion  of  the  disc 
appears  of  a  normal  color  {Fig.  14^),  while  in  glaucoma  there  is  a  greenish  shadow  run- 
ning along  the  papilla's  edge. 

The  diagnosis  of  simple  glaucoma  rests  upon  three  principal 
signs  :  impaired  vision,  excavation  of  the  disc,  and  increased  tension. 
If  this  last  sic^n  can  be  demonstrated  or  reco^inized  bv  its  results 


Fig.  145. — Ophthalmoscopic  Image  in  Physio- 
logical Optic-Nerve  Excavation.  (After 
Jaeger.) 


Fig.  146. — Ophthalmoscopic  Image  in  Glau- 
comatous Optic-Nekve  Excavation.  {After 
Jaeger.) 


(shallow  anterior  chamber,  dilated  and  sluggish  pupil,  arterial  pulse), 
the  matter  is  easy  enough  ;  but  tension  is  not  demonstrably  in- 
creased in  all  cases,  and  the  diagnosis  is  then  rather  difficult. 
There  are  several  reasons  why  the  increase  in  tension  in  simple 
glaucoma  is  not  infrequently  undetected.  First,  because  the  internal 
pressure  has  been  guessed  at  by  the  sense  of  touch,  instead  of 


GLAUCOMA    SIMPLEX.  399 

measured  by  a  practical  tonometer  (/.  /jp),  which  might  have 
supplied  trustworthy  evidence.  Second,  it  may  be  assumed  that 
tension  is  increased  only  at  intervals  ;  this  accords  with  the  fact 
that  in  simple  glaucoma,  also,  haziness  and  the  appearance  of  colored 
rings  around  flames  are  noticed  only  at  intervals.  Finally,  it  must  be 
remembered  that  there  are  hard  eyes  and  soft  eyes,  but  that  in  neither 
does  the  tension  go  beyond  the  normal ;  and  that  the  resistance  of 
the  optic-nerve  sheath  is  not  the  same  in  all  eyes.  It  may  therefore 
happen  that  a  moderate  increase  in  tension  in  an  originally  soft  eye, 
with  a  disc  lacking  resistive  power,  may  result  in  an  excavation, 
although  the  eye  appears  no  more  than  "  physiologically  hard." 

All  these  explanations  are  still  unsatisfactory,  since  there  are  cases  in  which  an  arti- 
ficial reduction  of  tension  does  not  at  all  check  the  decline  of  visual  acuity.  We  must, 
therefore,  assume  that  occasionally  there  are  cases  diagnosticated  and  treated  as  "  simple 
glaucoma,"  which  flepend  upon  accidental  coincidence  of  physiological  excavation  and 
some  form  of  optic-nerve  atrophy. 

The  difierentiation  of  these  cases  may  be  very  difficult.  It  is  relatively  easy  if  the  disc 
of  the  other  eye  is  smooth,  for  a  deep  excavation  in  the  diseased  eye  must  be  due  to  pres- 
sure— pathological — and  cannot  be  physiological.  If  this  distinction  is  lacking,  continued 
observation  of  the  patient,  or  careful  study  of  his  own  case  by  himself,  will  be  the  only 
means  of  furnishing  proof  that  increase  in  tension  does  occasionally  occur,  and  that, 
therefore,  the  disease  is  to  be  considered  glaucoma. 

The  preceding  description  makes  it  evident  that  inflammatory 
and  simple  glaucoma  are  only  different  forms  of  the  same  disease, 
but  that  for  practical  purposes  it  is  necessary  to  consider  each  as  a 
distinct  pathological  picture.  The  intimate  connection  between 
them  can  be  seen  in  various  clinical  manifestations.  For  example, 
cases  have  been  reported  where  simple  glaucoma  was  found  in  one 
eye  and  inflammatory  glaucoma  in  the  other  of  the  same  individual ; 
simple  glaucoma  has  of  a  sudden  changed  into  the  inflammatory 
form,  the  obvious  reason  being  that  the  hitherto  moderate  tension 
became  suddenly  alariningly  increased.  The  reverse  has  happened  : 
oftener  than  the  surgeon  likes,  probably,  he  discovers  that  an  eye, 
after  an  operative  cure  of  an  inflammatory  glaucoma,  gradually 
becomes  hard  again,  that  the  visual  field  becomes  narrower,  the 
visual  acuity  reduced — in  other  words,  that  a  simple  glaucoma  has 
replaced  the  inflammatory  glaucoma  supposed  to  be  cured.  More- 
over, it  must  be  observed  that  there  are  various  stages  between  the 
inflammatory  and  simple  (non-inflammatory)  glaucoma  ;  such  inter- 
mediate conditions  being  sometimes  grouped  apart  as  "  chronic 
inflammatory  glaucoma."  (/.  Jp6). 


400  GLAUCOMA. 

(c)  Glaucoma  Infantile  {Glaiicovia  of  Childhood),  Hydrophthal- 
mos  or  Buphthalmos  Congenitus. — Considering  the  delicacy  and 
tenderness  of  fetal  and  children's  tissue,  it  is  easy  to  see  that  increased 
tension  will  stretch  a  fetus'  or  child's  eyeball.  Consequently,  in 
infantile  glaucoma  a  pathological  picture  is  developed  which  bears 
but  little  external  resemblance  to  the  glaucoma  of  adults.  The  es- 
sential resemblance,  however,  is  seen  in  the  increased  tension  and  in 
the  gradually  resulting  excavation  of  the  optic-nerve  disc.  The  earli- 
est changes  will  be  noticed  in  the  cornea ;  this  becomes  larger  than 
normal,  the  diameter  of  the  circumference  at  the  margin  between 
cornea  and  sclera  being  as  great  as  ig  mm.  The  cornea  is  more 
or  less  hazy,  and  there  are  blood-vessels  at  its  edge.  Such  a  con- 
dition may  lead  to  comparison  with  keratitis  parenchymatosa. 
The  tension  must  therefore  be  carefully  tested,  a  difficult  matter  in 
children,  and  often  impossible  without  resort  to  narcosis.  The  an- 
terior chamber  is  extraordinarily  deep — 12.8  mm.  in  one  case  !  The 
iris  is  dull  and  lusterless,  the  pupil  dilated,  sluggish,  or  rigid.  The 
lens  is  small,  sometimes  cloudy,  and  insecure,  owing  to  stretching 
of  the  suspensory  ligament. 

B.  SECONDARY  GLAUCOMA. 

Many  diseases  of  the  eye  may  cause  increased  tension.  This 
increase  in  tension  is  called  secondary  glaucoma  in  case  it  is  pro- 
nounced and  lasting  enough  to  influence  the  visual  field  and  visual 
acuity.  Since  it  is  sometimes  difficult  or  impossible  to  say  in  an 
individual  case  whether  impaired  vision  is  due  to  the  original  dis- 
ease alone,  or  to  the  increase  in  tension,  the  expression  "  secondary 
glaucoma"  enjoys  a  remarkable  elasticity.  Secondary  glaucoma 
has,  of  course,  the  same  effect  as  primary  glaucoma. 

{ci)  Among  diseases  of  the  iris,  total  synechia  (/.  2'j'f)  plays  the 
most  important  part.  The  reason  for  increased  tension  is  in  this 
case  very  evident.  The  natural  current  from  the  posterior  to  the 
anterior  chamber  is  blocked,  and  the  fluid  secreted  by  the  ciliary 
body  must  therefore  overfill  all  this  space,  as  is  evidenced  by  the 
bulging  forward  of  the  iris.  Less  certain  to  lead  to  increased  ten- 
sion are  isolated  adhesions  of  the  ciliary  edge  of  the  iris  to  the 
cornea,  or  to  a  scar  in  the  sclero-corneal  margin.  The  causal  con- 
nection is  nevertheless  quite  evident.     (See  Theories,  p.  402.) 

{b)  Among  diseases  of  the  ie7is,  injuries  and  luxations  are  the 
principal  conditions  leading  to  increased  tension.     With  reference 


PATHOLOGICAL   ANATOMY.  4OI 

to  injuries  to  the  capsule  the  question  has  already  been  discussed 
in  the  section  on  traumatic  cataract  (/.  Jjp).  The  swollen  lens  sub- 
stance is  the  more  certain  to  cause  increased  tension,  the  more  capa- 
ble of  swelling  the  lens  is,  and  the  more  rigid  the  sclera.  Elderly 
persons  are  more  in  danger  than  the  young,  chiefly  on  account  of 
the  rigidity  of  the  sclera.  How  a  luxation  of  the  lens  can  cause 
glaucoma  is  not  so  clear.  The  best  explanation  is  that  the  mova- 
ble lens  irritates  the  ciliary  body  by  dragging  on  the  zonule  of  Zinn, 
exciting  it  to  pathological  secretion  and  to  inflammation. 

(c)  Retina. — Atheroma  of  the  retinal  vessels  not  infrequently 
causes  hemorrhage.  From  two  to  eight  weeks  later  there  is  in- 
creased tension  and  "  hemorrhagic  glaucoma."  This  form  is  par- 
ticularly dangerous,  and  in  spite  of  prompt  treatment  usually  ends 
in  blindness. 

(^)  Tumors  of  the  interior  of  the  eye,  particularly  of  the  ciliary 
body,  may  cause  increased  tension  by  occupying  all  the  space,  and 
perhaps  by  hindering  the  discharge  of  lymph  from  the  eye. 


3.  PATHOLOGICAL  ANATOMY. 

The  number  of  glaucomatous  eyes  that  have  been  examined 
microscopically  is  large,  but  most  of  them  were  already  blind  and 
were  removed  for  the  severe  pain  they  caused.  The  changes  found 
in  them  are,  therefore,  doubtless  in  great  part,  not  causes  but  re- 
sults of  glaucoma,  and  of  but  little  value  in  support  of  any  "  glau- 
coma theories." 

Leber  found  droplets  in  the  epithelium  of  glaucomatous  corneae, 
and  Fuchs  in  both  epithelium  and  cornea  proper,  particularly  in 
the  anterior  layers.  Fuchs  consequently  denominates  glaucoma- 
tous corneal  opacity  as  "  inflammatory  edema"  (/>.  ^5j). 

The  neighborhood  of  the  canal  of  Schlemm  is,  according  to 
Knies,  infiltrated  with  round  cells  even  before  the  real  disease  be- 
gins, and  the  same  is  true  of  the  root  of  the  iris  and  of  the  ciliary 
body.  As  the  disease  progresses  there  may  be  a  circular  adhesion 
of  the  root  of  the  iris  to  the  posterior  surface  of  the  cornea,  which 
would  obliterate  the  recess  in  the  anterior  chamber  between  them 
and  block  up  the  chief  channels  of  the  circulation  within  the  eye. 

Iris  and  ciliary  body  show  at  first  round-cell  infiltration,  and  later 
atrophy ;  and  this  round-cell  infiltration  has  been  found  in  the  cho- 
26 


402^  GLAUCOMA. 

roid,  particularly  along  the  veins.  Hyaline  degeneration  of  the 
vessel  walls  has  been  described,  as  well  as  atheroma  of  these  ves- 
sels and  of  those  in  the  retina  (hemorrhagic  glaucoma). 

In  the  optic  nerve  are  found  the  most  important  and  most  regu- 
larly occurring  changes.  According  to  Schnabel  they  are  due  to 
an  interstitial  neuritis  in  the  part  of  the  nerve  still  provided  with  its 
medulla,  that  is,  behind  the  eyeball ;  or  to  inflammation  or  mere 
atrophy  of  the  nervous  and  connective-tissue  elements  in  the  optic- 
nerve  sheath. 


4.  THEORIES. 

In  speaking  of  secondary  glaucoma  it  was  pointed  out  that  some  cases  need  no  theorj*, 
that  is,  no  explanation  built  up  from  assumptions.  As  a  matter  of  fact,  increased  tension 
resulting  from  swollen  lens  substance,  or  from  a  tumor  increasing  faster  than  the  vitreous 
can  decrease,  or  from  total  synechia,  explains  itself.  In  the  first  two  cases  it  is  the  in- 
crease in  the  contents  of  the  eyeball,  in  the  last  the  retarded  circulation  between  posterior 
and  anterior  chambers,  which  causes  the  inqrease  in  tension. 

But  what — in  other  cases  of  glaucoma,  esjjecially  the  primary  forms  — causes  the 
increase  in  tension  ?  Is  it  the  blood  pressure  ?  Then  without  doubt  the  tension  of  the 
eyeball  will  be  a  criterion  of  the  blood  pressure.  The  attempt  has  been  made  on  ani- 
mals to  raise  the  eye's  tension  by  pressure  on  or  ligation  of  the  jugular  veins,  but  this  by 
no  means  produced  glaucoma.  Moreover,  it  is  known  from  observations  on  men  with  high 
blood  pressure — fever  patients,  for  example — or  on  men  with  low  blood  pressure — those 
near  death — that  the  internal  tension  of  the  eye  is  very  far  from  following  the  variations 
of  the  blood  pressure.  Again,  the  assumption  that  disease  of  the  iritic  or  choroidal  vessels 
can  block  the  circulation  and  cause  stasis  needs  a  much  more  substantial  support  of 
pathological  facts  than  we  have  as  yet. 

The  study  of  the  circulation  in  the  eye  (/.  26g)  has  been  productiv^e  of  more  fruitful 
results.  In  order  to  retain  the  internal  tension  of  the  eye  at  a  normal  equilibrium,  there 
must  also  be  equilibrium  between  the  secretion  of  the  ocular  fluid  on  the  one  hand,  and 
its  escape  on  the  other.  Hindrance  to  the  escape  of  fluid,  or  increase  in  its  secre- 
tion, or  both  together,  must  cause  increased  tension.  Many  ophthalmologists  lay  par- 
ticular stress  upon  the  hindrance  to  the  escape  of  fluid,  assuming,  with  Knies,  that  the 
essential  and  final  cause  of  glaucoma  is  an  inflammatory  infiltration  at  the  root  of  the  iris 
and  at  the  sclero-corneal  margin.  The  resultant  cicatricial  contracture  would  block  up 
the  angle  between  iris  and  cornea,  where  the  principal  drainage  canal  for  the  aqueous 
lies.      Increased  tension  \vith  all  its  consequences  would  naturally  result  from  it. 

Other  ophthalmologists  contend  that  the  shallowness  of  the  anterior  chamber  stands 
in  direct  contradiction  to  this  theory.  It  is  evident  that  hindrance  in  the  path  of  a  stream 
must  cause  backward  stasis  and  a  consequent  broadening  of  the  path  itself.  It  is,  there- 
fore, more  logical  to  consider  the  blocking  up  of  the  angle  to  be  rather  the  result  of 
increased  tension,  the  cause  being  sought  in  increase  in  the  eye's  contents  lying  behind 
the  iris  and  lens.  In  favor  of  this  "  secretion  theorj'  "  it  may  be  adduced  that  many  cir- 
cumstances indicate  that  primary  glaucoma  is  connected  with  disturbances  in  the  nervous 
system.     For  example,  in  many  cases  trigeminal  neuralgia  precedes  an  attack  of  glau- 


PROGNOSIS    AND    TREATMENT.  4O3 

coma  ;  or  glaucoma  may  appear  at  intervals  with  the  peculiar  characteristics  of  neuralgia  ; 
or  glaucoma  may  often  be  produced  by  mental  states  of  shock  and  anxiety.  ^ 

Again,  many  of  the  phenomena  of  secretion  are  directly  under  the  influence  of  the 
nervous  system — the  secretion  of  tears,  for  example.  By  artificial  stimulation  of  the  cili- 
ary ganglion  in  dogs  the  internal  tension  of  the  eye  can  be  noticeably  and  permanently 
raised,  and  we  may  therefore  assume  that  when  this  ganglion  is  stimulated,  the  secretion 
of  fluid  is  increased,  and  that  glaucoma  depends  upon  an  analogous  process. 

This  by  no  means  exhausts  the  number  of  glaucoma  theories,  but  there  is  nothing  to 
be  gained  by  pursuing  the  subject  farther,  for  theories  that  appear  to  one  man  to  solve 
the  problem  seem  to  another  as  mere  fantasies  of  the  brain.  It  may  be  mentioned,  per- 
haps, that  Schoen,  after  years  of  study  and  investigation,  ascribes  glaucoma  to  overexer- 
cise  of  the  accommodation,  and  would  lay  more  weight  upon  prophylaxis  of  glaucoma  by 
properly  selected  glasses  than  upon  mere  operative  treatment. 

I  once  performed  an  iridectomy  for  the  ripening  of  cataract.  Both  eyes  were  soft, 
the  anterior  chamber  noticeably  deep,  and  there  was  no  suspicion  of  glaucoma.  Imme- 
diately after  the  iridectomy  the  anterior  chamber  filled  with  blood.  The  next  day  the 
blood  was  to  a  large  extent  absorbed,  and  I  then  gave  atropin.  When  the  bandage  was 
again  changed  it  was  spotted  with  blood,  there  was  blood  in  the  conjunctiva  and  in  the 
anterior  chamber.  I  feared  an  injury,  but  on  the  next  day  the  blood  was  again  dimin- 
ished. Unsuspectingly,  I  again  gave  atropin.  On  the  next  day  the  eye  was  as  hard  as 
a  stone,  the  cornea  cloudy,  the  chamber  full  of  blood — hemorrhagic  glaucoma.  With 
eserin,  cocain,  and  warm  compresses  the  cyclone  passed  by,  with  no  worse  results  than 
a  line  of  delicate  posterior  synechia. 

This  case  shows  that  in  spite  of  deep  anterior  chamber,  in  spite  of  softness  of  tension, 
in  spite  even  of  a  preceding  iridectomy,  an  eye  may  be  the  victim  of  glaucoma ;  the  case 
supports  the  suspicion,  too,  that  the  disposition  to  glaucoma  consists  of  a  pathological 
character  of  the  blood-vessels,  and  that  an  attack  of  glaucoma  is  excited  by  the  nervous 
system  ;  for  the  effect  of  atropin  upon  the  smooth  muscular  fibers  in  the  eye,  and  there- 
fore upon  the  condition  of  the  vascular  walls,  is  probably  brought  about  by  paralysis  of 
the  peripheral  nerve-endings. 


5.  PROGNOSIS  AND  TREATMENT. 

Every  case  of  glaucoma,  if  untreated,  will  surely  end  in  complete 
and  incurable  blindness.  It  is,  therefore,  much  to  be  regretted  that 
many  and  many  a  time  the  error  is  made  by  physicians  of  diagnos- 
ticating any  decline  in  visual  acuity  in  elderly  persons  as  due  to 
cataract,  and  that  physicians  send  such  patients  to  the  ophthal- 
mologist only  when  the  neglected  "  simple  glaucoma"  has  already 
approached  the  stage  of  incurable  blindness.  Quite  as  serious  is 
it  to  confuse  acute  glaucoma  with  iritis,  a  mistake  that  would  seem 
impossible  if  the  dilated  pupil  of  glaucoma  is  considered,  and  yet  it 

^  This  explains  the  fact  that  often  enough  during  operative  treatment  for  glaucoma  on 
one  eye,  the  other  sound  eye  is  attacked  by  the  disease.  It  is  advisable,  therefore,  dur- 
ing an  operation  for  glaucoma  to  instil  eserin  or  pilocarpin  into  the  apparently  healthy  eye. 


404  GLAUCOMA. 

is  made  again  and  again.  Overlooking  the  effect  of  such  serious 
errors,  the  prognosis  is  decidedly  favorable  for  acute  glaucoma  if 
treated  properly,  doubtful  for  simple  and  infantile  glaucoma,  and 
unfavorable  for  hemorrhagic  glaucoma. 

The  aim  of  treatment  is  the  reduction  of  tension.  To  reach  this 
goal  we  have  three  methods  at  our  command : — 

(i)  Medication,  by  eserin  or  pilocarpin. 

(2)  Massage. 

(3)  Operation,  by  corneal  puncture,  iridectomy,  sclerotomy,  and 
(the  newest)  incision  of  the  ligamentum  pectinatum. 

The  effect  of  myotics  such  as  eserin  and  pilocarpin,  as  well  as 
that  of  their  antagonists,  the  mydriatics — atropin,  homatropin,  and 
cocain — has  already  been  discussed  (/.  2'jo).  We  need  mention 
here  only  their  effect  on  the  eye's  internal  tension.  In  the  healthy 
eye  they  produce  no  appreciable  change  in  tension.  Cocain  is  an 
exception,  for  it  has  been  frequently  observed  that  healthy  eyes  of 
elderly  persons  are  made  noticeably  soft  by  cocain.  The  effect 
may  be  quite  different  if  there  is  a  pathological  increase  of  tension 
already  present.  Myotics  reduce  tension,  but  mydriatics,  even 
cocain  at  times,  increase  it.  To  use  atropin  if  there  is  the  least 
suspicion  of  glaucoma  is,  therefore,  unconditionally  forbidden,  and 
even  homatropin  or  cocain  are  to  be  used  only  with  the  greatest 
caution. 

The  connection  between  dilatation  of  the  pupil  and  increased  tension  is  not  quite  clear. 
Many  suppose  that  the  iris  when  dilated  rolls  up  into  the  filtration  angle  and  retards  the 
outflow  of  aqueous,  and  that  contrariwise  an  expanded  iris  leaves  free  the  filtration  angle, 
and  therefore  offers  no  obstruction  to  the  principal  outlet  for  the  eye's  fluids.  The  fact 
admits  of  other  explanations,  however. 

Glaucoma  cannot  be  healed,  but  single  attacks  may,  in  favorable 
cases,  be  cut  short  by  means  of  pilocarpin  or  the  stronger  eserin. 
These  remedies  are  therefore  of  inestimable  value,  especially  if  the 
problem  is  to  obviate  the  danger  of  increased  tension  until  the  pa- 
tient can  consult  an  ophthalmologist.  Myotics  are  also  of  value  in 
simplifying  the  performance  of  a  sclerotomy  or  an  iridectomy. 
And,  finally,  they  are  used  extensively  in  the  after-treatment. 

The  second  method,  massage,  is  used  principally  in  the  after- 
treatment,  and  in  cases  of  simple  glaucoma  for  which  one  or  more 
futile  operations  have  been  performed,  and  in  which,  therefore,  the 
surgeon's  task  is  to  retard  as  long  as  possible  the  unavoidable  decline 
in  visual  acuity.     The  result  of  massage  is  instantaneous,  the  hard 


PROGNOSIS    AND    TREATMENT.  405 

eyeball  grows  soft  under  the  physician's  finger,  so  to  say,  but  its 
effect  is  not  lasting.  The  patient  should,  therefore,  learn  to  mas- 
sage himself,  and  practice  it  daily.  In  massage  it  is  quite  prac- 
tical to  use  a  salve  containing  eserin  and  cocain :  Eserin  stilf., 
0.02 §  ;  Cocain  muriat,  0.2^  ;  Vaselin,  ^.o. 

Corneal  puncture  is  a  method  of  the  moment.  As  the  aqueous 
escapes  the  contents  of  the  eyeball  is  of  course  reduced,  the  tension 
decreases,  the  consequences  of  the  previously  increased  tension 
disappear — for  a  short  time  only.  The  essentially  curative  method 
in  glaucoma  is  iridectomy  {p.  286).  A.  v.  Graefe  devised  it,  and  it  is 
one  of  the  services  he  performed  for  science  which  renders  his 
name  immortal.  Preparations  to  prevent  infection  are  the  same  as 
in  the  operation  for  cataract  {p.  351)-  If  the  anterior  chamber  is 
shallow  (as  it  usually  is)  and  the  iris  small,  the  careful  performance 
of  a  broad  iridectomy  extending  to  the  ciliary  border  is  made  un- 
usually difficult  and  of  danger  to  the  lens.  It  may  be  somewhat 
facilitated  by  instilling  eserin  in  advance,  and  by  making  the  in- 
cision with  V.  Graefe's  cataract  knife  {Fig.  126,  p.  34.8)  instead  of  with 
the  keratome  ;  of  course,  with  the  knife  the  iridectomy  can  be  made 
only  above  or  below.  Iridectomy  upward  is  almost  always  the  rule, 
since  the  space  left  by  removal  of  part  of  the  iris  is  covered  by  the 
upper  lid.    The  incision  should  lie  in  the  opaque  tissue  of  the  sclera. 

The  effect  of  an  iridectomy  in  cases  of  acute  glaucoma  is  extra- 
ordinarily favorable.  Tension  becomes  normal  and  all  visual  dis- 
turbances due  to  increased  tension  disappear.  Visual  acuity  may, 
in  the  course  of  time,  become  normal,  even  when  it  has  been  reduced 
to  counting  fingers  or  to  a  mere  perception  of  light  from  darkness. 
How  this  effect  is  produced  is  at  present  as  much  a  matter  of  dis- 
cussion as  is  the  nature  of  glaucoma  itself. 

In  my  experience  I  have  very  often  seen  posterior  synechiae 
(plastic  iritis)  after  an  iridectomy,  in  spite  of  the  most  scrupulous 
antisepsis.  I  suppose  that  it  is  to  be  ascribed  not  to  infection  but 
to  increase  in  the  inflammatory  condition  which  the  glaucoma  had 
produced  in  the  iris.  The  iritis  can  be  antagonized  with  cocain  or, 
in  some  cases,  with  homatropin  and  with  warm  compresses  of 
boric  acid  solution — compresses  being  used,  of  course,  only  after 
the  wound  has  healed  and  the  anterior  chamber  filled. 

Iridectomy  makes  a  hole  in  the  iris  which,  if  it  lies  below  the  palpebral  fissure, 
causes  dazzling  and  distortion.  There  is,  as  a  rule,  a  change  in  the  shape  of  the  cornea, 
evidenced  by  an  astigmatism  that  somewhat  influences  visual  acuity.     Not  infrequently 


406  GLAUCOMA. 

there  are  hemorrhages  in  the  retina  as  the  restilt  of  the  sudden  reduction  of  the  internal 
pressure.  In  case  they  are  in  the  center  of  the  retina  they  cause  noticeable  visual  dis- 
turbances ;  if  very  numerous,  they  may  be  quite  destructive,  but,  as  a  rule,  they  are  with- 
out serious  effect.  They  should  be  avoided  by  allowing  the  aqueous  to  escape  very 
slowly  during  or  after  the  completion  of  the  incision.  The  scar  in  the  sclera  made  for 
glaucoma  is  somewhat  peculiar;  it  is  broader  and  strewn  with  dark  spots,  while  an  iri- 
dectomy in  a  healthy  eye  leaves  a  very  narrow,  or.  perhaps,  an  invisible  scar.  These 
dark  spots  are  from  the  glistening  pigment  of  the  iris  or  ciliary  body.  The  scar  tissue 
often  shows  little  vesicular  elevations ;  such  a  scar  is  called  cystoid.  In  case  a  cystoid 
scar  does  not  of  itself  contract,  it  may  be  obliterated  by  the  cautery. 

In  many  cases  glaucoma  is  cured  by  an  iridectomy  and  remains 
so.  In  others  tension  increases  again  after  a  longer  or  shorter 
interval,  and  the  result  is  the  picture  called  simple  or  chronic  inflam- 
matory glaucoma.  It  is  evident  that  in  simple  glaucoma  iridectomy 
can  be  of  but  little  service,  since  the  visual  disturbance  depends 
essentially  upon  the  changes  in  the  optic  nerve,  which,  even  in  the 
best  cases,  can  be  brought  to  a  standstill  but  not  overcome.     In 


Fig.  147. — Sclerotomy. 

about  one-third  of  the  cases  even  this  result  is  not  obtained.    Effort 
has  been  made,  therefore,  to  find  some  other' method  of  treatment, 
and  sclerotomy  was  resorted  to.     According  to  v.  Wecker,  iridec- 
tomy is  to  be  replaced  by  sclerotomy — 
(i)  In  certain  cases  of  simple  glaucoma. 

(2)  In  infantile  glaucoma. 

(3)  In  hemorrhagic  glaucoma. 

A  prime  condition  is  that  the  pupil  can  be  well  contracted  by 
eserin.  The  operation  is  performed  in  the  following  way :  A 
V.  Graefe's  cataract  knife  is  introduced  /  mm.  from  the  corneal  edge 
(at  a,  Fig.  i^y)  into  the  anterior  chamber  and  is  brought  out  at  a 
corresponding  point  (at  b)  on  the  other  side.  The  tissue  is  now 
cut  with  saw-like  motions,  as  if  a  flap  were  to  be  formed,  but  finally 
a  bridge  of  tissue  is  left  just  about  as  long  as  each  of  the  two  inci- 
sions. As  the  knife  is  withdrawn,  its  point  should  be  brought  into 
the  filtration  angle  and  the  "  arch  of  the  spaces  of  Fontana  "  cut 


CYSTICERCUS.  4O7 

through.  This  last  step  in  sclerotomy — the  incision  of  the  liga- 
mentum  pectinatum — has  been  performed  by  Taylor  as  an  opera- 
tion of  itself  for  glaucoma,  with  good  results. 

Sclerotomy  is  said  to  make  a  "  filtration  scar,"  that  is,  to  provide 
porous  tissue  for  the  aqueous.  According  to  this,  a  cystoid  scar 
ought  to  be  the  type  of  a  filtration  scar,  but  even  after  a  cystoid 
cicatrization,  tension  may  rise  again.  The  good  effect  of  sclerotomy 
is  therefore  not  yet  quite  clear.  In  the  patients  I  have  treated  with 
sclerotomy  I  have  only  twice  seen  a  really  satisfactory  reduction  of 
tension. 

If  the  iris  tissue  is  atrophic,  iridectomy  usually  produces  no  perceptible  reduction  of 
tension.  The  operation  may  also  be  incomplete.  It  may  happen  that  neither  iridectomy 
nor  anterior  sclerotomy  is  applicable,  because  the  iris  is  atrophic,  the  anterior  chamber 
very  shallow,  and  the  pupil  unaffected  by  eserin.  In  such  a  case  we  may  try  posterior 
sclerotomy,  that  is,  a  meridional  section  through  sclera  into  vitreous,  which  allows  some 
fluid,  yellowish  vitreous,  to  escape.  I  have  several  times  resorted  to  this  method  with 
comparatively  good  success.  For  example,  I  have  now  a  patient  with  visual  acuity  and 
visual  field  about  as  they  were  two  years  ago  when  she  came  to  me  for  treatment  on  ac- 
count of  relapsing  glaucoma ;  during  this  time  I  have  performed  posterior  sclerotomy 
twice  on  each  eye,  instilled  pilocarpin,  and  ordered  daily  massage.  The  patient  stopped 
the  treatment  several  times  on  her  own  responsibility,  but  the  rainbow  vision  returned, 
and  she  was  only  too  glad  to  begin  vigorous  massage  and  pilocarpin  treatment  once  more. 


ENTOZOA— PARASITES  IN  THE  EYE. 

J.  CYSTICERCUS. 

The  larva  of  the  tape-worm  (taenia  solium)  is  called  cysticercus 
cellulosae.  It  may  be  found  in  all  parts  of  the  human  body. 
These  larvae  cause  disturbances  chiefly  when  located  in  the  brain 
and  in  the  eye,  the  latter  location  only  being  of  interest  to  us.  How 
does  the  larva  reach  the  eye  ?  It  is  found  in  men  in  whom  a  tape- 
worm has  already  found  lodgment,  or  in  those  who  are  bedfellows 
of  tape-worm  patients,  or  in  others  in  whom  no  tape-worm  infection 
can  be  demonstrated.  A  tape-worm  host  can  infect  himself,  either 
because  the  segments  reach  the  stomach  from  the  intestine  during 
vomiting,  or  because  the  eggs  are  carried  by  dirty  fingers  and  swal- 
lowed with  the  food.  This  may  be  the  same  process  by  which  a 
person  becomes  infected  from  a  companion.  In  any  case  the  egg 
of  the  tape-worm  inust  reach  the  stomach.  The  gastric  juice  dis- 
solves  the  shell  of  the  egg,  the  embryo  is  released,  pierces  the 


4o8 


ENTOZOA PARASITES    IN    THE    EYE. 


SBoefy- 


Fig  148.— Cysticbrcus, 
WITH  Extended 
Head  AND  Neck.  (Af- 
ter Stein.) 


stomach  wall,  reaches  the  blood  current,  and  lodges  finally  in  the 
eye. 

The  cysticercus  consists  of  head,  neck,  and  body  (vesicle)  {Fig. 
148).     The  head  bears  four  suckers  and  a  row  of  hooklets.     Head 
and  neck  may  be  withdrawn  into  the  body  so  that  the  whole  figure 
looks  like  a  bladder  {Fig.  i^g)  of  ^  mm.  diameter,  in  which  a  white, 
opaque    spot    may  be  recognized  as    the    head 
with  its  suckers.    The  parasite  floats  in  a  second 
bladder  filled  with  fluid ;  it  is  supposed  that  this 
external  vesicle — the  house  of  the  larva — is  sup- 
plied by  the  tissue  of  the  host. 

The  larva  has  been  found  beneath  the  skin  of 
the  lids,  below  the  conjunctiva,  within  the  orbit, 
in  the  anterior  chamber,  in  the  vitreous,  and  be- 
hind the  retina.  The  commonest  occurrence  is 
that  the  larva  rests  at  first  behind  the  retina,  and  during  its  growth, 
either  with  or  without  the  external  vesicle,  breaks  into  the  vitreous. 
Such  a  case  is  most  important,  not  only  on  account  of  its  com- 
parative frequency,  but  also  with  reference  to  its  treatment,  and  is, 
therefore,  used  as  the  basis  for  the  following  description : — 

The  first  sign  of  the  larva  within  the  eye  is  a  visual  disturbance 
in  the  form  of  a  dark  spot,  whose  location  in  the  visual  field  is 
dependent  upon  the  location  of  the 
larva  in  the  eye.  Later  on,  there  is 
distortion  and  finally  cloudiness  of 
the  entire  visual  field,  and  consequent- 
ly a  reduction  of  vision,  even  if  the 
larva  lies  eccentrically  in  the  fundus. 
In  cases  observed  by  v.  Graefe  from 
the  beginning  with  the  ophthalmo- 
scope, there  was  at  first  a  bluish- 
gray  haziness  at  a  certain  spot  on  the 
fundus.  This  opacity  grew  larger 
during   the    succeeding    weeks    and 

protruded  distinctly.  Then  the  larva  burst  out  of  the  apex  of 
the  protrusion,  into  the  vitreous ;  or  in  other  cases  it  first  made 
a  path  downward  between  retina  and  choroid  before  it  finally 
broke  out.  The  original  location  of  the  larva  remained  a 
grayish-blue  spot  with  white,  somewhat  prominent  edges.  If 
the   larva   is   seen    while   the    vitreous   is    still    unclouded,    the 


Cysticercus. 
Head. 


-    External  vesi- 
cle. 


Fig.  149. — Cysticercus,  with  Neck 
AND  Head  Withdrawn,  Lying  in  the 
External  Vesicle.     {Ajter  Stein.) 


CYSTICERCUS. 


409 


recognition  of  the  disease  is  easy.  The  examination  in  the  in- 
verted image  should  be  made  with  a  strong  convex  lens  (25.0  D) 
in  order,  if  possible,  to  see  the  whole  larva  atone  time.  We  would 
find  a  blue-gray  vesicle  about  four  times  the  diameter  of  the  papilla, 
the  edges  of  the  vesicle  being  a  sharply  defined,  yellowish-red,  glis- 
tening circumference;  the  play  of  color  on  the  circumference  is 
seen  most  distinctly  in  the  upright  image  by  rotating  the  mirror. 
Not  unfrequently  we  may  succeed  in  detecting  through  the  exter- 
nal vesicle  movements  of  the  larva  itself;  this  is  particularly  easy 
if  the  larva  is  naked,  that  is,  if  it  lies  in  the  vitreous  [Fig.  ijd)  or 
in  the  anterior  chamber  without  any  second  vesicle.     We  see  peri- 


FiG.  150. — Ophthalmoscopic  Imark  of  a  Livinc;  Cysticercus  in  the  Vitreous. 
{After  Liebreich.) 


staltic-like  movements  passing  up  and  down  the  vesicle,  and  if  they 
are  very  active  they  give  a  swing-like  motion  to  the  whole  body. 
The  picture  is  most  fascinating  if  the  animal  extends  its  neck  and 
head  with  its  suckers  and  moves  itself  about  in  an  apparently  tire- 
less way. 

This  condition  may  last  for  weeks  or  months,  but  gradually  the 
parasite  or  its  morphological  products  will  act  as  a  source  of  irrita- 
tion ;  the  vitreous  becomes  opaque,  obscuring  the  image,  but  of  it- 
self possessing  such  characteristics  that  the  condition  will  establish 
the  diagnosis  for  one  who  has  had  experience.  These  vitreous 
opacities  are  like  curtains  looped  together,  extending  through  the 
entire  vitreous,  somewhat  transparent  and  slightly  movable,  the 


4IO  ENTOZOA PARASITES    IN    THE    EYE. 

appearance  being  quite  different  from  that  presented  by  the  torn 
and  untransparent  lumps,  threads,  and  shreds  of  the  usual  vitreous 
opacities.  On  account  of  their  relative  transparency  they  permit 
for  a  long  period  the  recognition,  at  a  certain  spot  on  the  fundus, 
of  a  bright,  bluish-gray  reflex — the  larva. 

These  opacities  become  denser,  the  retina  finally  prolapses,  until 
the  diagnosis  becomes  impossible,  or  can  be  only  conjectured. 
Finally,  we  find  numerous  signs  of  a  chronic  iridochoroiditis.  It 
need  scarcely  be  mentioned  that  at  this  stage  all  vision  has  been 
long  since  obliterated.  With  varying  cessations  or  relapses  of  the 
pain  and  other  symptoms  of  inflammation  the  eye  becomes  soft 
and  contracted.  The  sensibility  of  this  "  phthisical  "  eye  may  be 
gradually  lost,  and  the  eye  become  permanently  quiet.  Sympa- 
thetic inflammation  is  not  to  be  feared. 

Prognosis  is  always  unfavorable.  Without  interference  every 
parasite  causes  blindness  in  the  eye  attacked  within  three  to  ffteen 
months. 

Treatment  should  be  prophylactic  if  possible, — such  methods  as 
are  used  for  the  prevention  of  the  taenia  in  general.  Since  the  in- 
troduction of  a  municipal  meat  inspection,  cases  of  the  disease  in 
Berlin  have  become  noticeably  less.  Personal  cleanliness,  the 
avoidance  of  raw  meat,  ham,  and  sausage,  and  the  cure  of  tape- 
worm in  one's  self  or  in  one's  bedfellow,  must  be  insisted  on.  If  a 
larva  reaches  the  eye,  it  must  be  removed  by  operation,  which  con- 
sists of  a  meridional  scleral  incision  for  the  introduction  of  a  toothed 
forceps.  If  the  incision  has  been  properly  located,  the  delivery  of 
the  parasite  is  usually  an  easy  matter,  provided  that  it  is  not  float- 
ing freely  in  the  vitreous,  but  is  attached  to  the  eye-wall,  and  that 
the  opacity  of  the  vitreous  has  not  already  developed  beyond  the 
point  where  a  proper  localization  of  the  larva  is  still  possible.  If 
the  operation  is  done  early  enough,  that  is,  particularly  before  pro- 
lapse of  the  retina  has  resulted,  a  good  vision — even  V  =  / — may 
be  retained. 

Here  in  Zurich  a  cysticercus  is  the  greatest  rarity.  I  have  seen  only  one  case,  proba- 
bly the  first  in  Zurich,  and  I  operated  on  it.  The  patient  was  Swiss,  but  had  worked  for 
a  long  time  in  Hamburg  as  a  butcher.  The  eye  was  already  blind.  The  operation 
could  not,  therefore,  restore  vision,  but  only  prevent  inflammation  and  atrophy. 

The  rarity  of  the  parasite  in  the  eye  in  many  districts  is  remarkable,  considering  that 
in  these  very  districts  tape- worm  itself  is  by  no  means  uncommon.  For  example,  in  many 
localities  of  Switzerland  tape-worm  is  very  prevalent,  while  cysticercus  is  very  rare.  The 
explanation  may  lie  in  the  fact  that  not  all  tape-worms  are  capable  of  spreading  larvse 


FILARIA.  411 

through  the  human  body.     To  illustrate,  all  larvas  seen   in  the  eye  are  from  the  taenia 
solium,  while  the  tape-worm  so  common  on  Lake  Geneva  is  the  bothriocephalus. 


II.  FILARIA— (Thread-Worms). 

It  has  happened  repeatedly  that  remnants  of  the  embryonic  ar- 
teria  hyaloidea  have  been  taken  for  thread-worms.  Thread-worms 
have,  however,  been  found  in  opaque  lenses  removed  on  that 
account.  Kuhnt  has  recently  described  a  case  in  which  a  thread- 
worm was  seen  in  the  vitreous,  by  the  ophthalmoscope,  removed  by 
operation,  and  demonstrated  as  an  anatomical  specimen.  The 
matter  would  be  of  little  practical  interest  on  account  of  its  great 
rarity,  were  it  not  that,  as  Kuhnt  emphasizes,  the  possibility  ought 
to  be  thought  of  that  many  cases  of  retinitis  with  vitreous  opacities 
and  retinal  prolapses  of  unknown  origin  may  be  due  to  undiscov- 
ered parasites.  Independent  movements  of  the  questionable  object 
ought  to  be  of  great  importance  in  making  a  diagnosis. 


INJURIES  TO  THE  EYEBALL. 

Injuries  to  individual  parts  of  the  eye  have  been  already  dis- 
cussed in  previous  sections.  There  remains  for  discussion  the 
effect  of  an  injury  upon  the  eye  as  a  whole,  in  other  words,  how 
injuries  of  several  parts  are  associated  in  one  pathological  picture. 
In  view  of  the  extraordinary  complexity  of  such  pictures  a  descrip- 
tion of  all  of  them  is  scarcely  possible,  and  only  a  few  examples 
can  be  made  use  of.  It  is  therefore  unavoidable  that  something  of 
what  has  previously  been  said  should  be  repeated. 

Those  persons  are  most  often  injured  who  have  certain  danger- 
ous occupations,  stone-masons  or  bricklayers,  for  example.  Such 
injuries  connected  with  occupations  might  be  to  a  great  extent 
avoided  if  the  workmen  could  be  induced  to  wear  protecting  spec- 
tacles. 

Unfortunately,  this  is  seldom  done.  Man's  carelessness  to  the  danger  of  his  calling  is 
traditional.  A  mason,  from  whose  cornea  I  had  repeate  dly  removed  foreign  bcdies 
decided  finally,  at  my  request,  to  use  protecting  spectacles.  A  short  time  afterward  a 
large  splinter  struck  one  glass  and  smashed  it,  but  the  eye  was  uninjured,  a  splendid 
proof  of  its  efficiency.  The  mason,  however,  was  in  no  hurry  to  get  his  spectacles 
repaired,  and  soon  came  to  me  again  with  another  foreign  body  in  his  cornea. 


412  INJURIES    TO    THE    EYEBALL. 

I.  INJURIES  BY  PUNCTURE  AND  INCISION. 

Puncture  wounds  may  be  made  by  forks,  needles,  scissors,  thorns, 
pens,  and  such  sharp  implements  ;  incisions,  by  knives,  swords,  glass, 
and  the  sharp  edge  of  any  such  hard  objects.  The  danger  to  the 
eye  arising  from  such  a  wound  depends  not  only  upon  the  ana- 
tomical injury,  but  also  upon  whether  the  wound  has  or  has  not 
been  infected  by  pathological  germs.  The  dangers  of  infection  are 
greater  in  punctured  wounds  because  disinfection  by  the  physician 
is,  as  a  rule,  impossible  on  account  of  depth  and  narrowness  of  the 
traumatic  canal.  Piercing  wounds  of  the  sclero-corneal  margin  are 
particularly  to  be  feared,  because  the  ciliary  body  also  is  injured, 
or  prolapses  into  the  wound  and  becomes  incarcerated  in  the  scar. 
Such  adhesions  of  the  ciliary  body  lead  most  usually  to  chronic 
cyclitis  or  even  to  sympathetic  inflammation  of  the  other  eye. 

The  reason  of  the  danger  of  injury  to  the  ciliary  body  is  not  yet  satisfactorily  explained. 
We  may  suppose  that  the  entrance  of  germs  is  in  this  case  particularly  easy,  or,  perhaps, 
takes  place  subsequently  through  the  very  thin  scar ;  or  that  the  contraction  of  the  scar 
tissue  produces  a  laceration  in  the  sensitive  ciliary  body  which,  in  its  turn,  may  be  the 
cause  of  inflammation.  A  retraction  of  the  scar  is  always  a  sign  of  such  an  atrophy  and 
is  to  be  considered  the  eye's  death-warrant. 

Wounds  of  the  sclera  are  almost  always  accompanied  by  prolapse 
of  choroid  and  retina  and  by  more  or  less  loss  of  vitreous.  The 
unprolapsed  portion  of  the  retina  may  be  loosened — in  which  case 
perception  of  light  is  lacking  and  the  restoration  of  visual  energy 
must  be  given  up. 

An  important  question  in  every  injury  to  the  eyeball  is  as  to 
whether  or  not  the  lens  is  injured.  Every  injurj^  to  the  lens  cap- 
sule ends  in  traumatic  cataract  [p.  JJQ).  Injuries  to  the  lens, 
therefore,  impair  the  prognosis  materially,  all  other  conditions  being 
equal. 

Treatment  consists  in  radical  disinfection  of  lids  and  tear  sac  (if 
this  is  diseased),  in  douching  the  conjunctival  sac  with  /  :  jooo  sub- 
limate solution,  closure  of  the  wound  with  conjunctival  suture,  dust- 
ing with  finely  powdered  iodoform,  antiseptic  bandage,  and  rest.  If 
the  iris  has  prolapsed,  the  attempt  should  be  made  to  replace  it  by 
a  spatula  and  to  retain  it  in  place  by  eserin ;  if  this  does  not  suc- 
ceed, or  if,  by  reason  of  size  and  position  of  the  wound,  it  is  irre- 
placeable, the  prolapsed  portion  must  be  seized  with  forceps,  drawn 
out,  and  cut  off.     If  the  lens  capsule  is  injured,  atropin  and  ice 


INJURIES    BY    BLUNT    INSTRUMENTS.  4I3 

compresses  are  to  be  used.  In  case  the  retina  is  completely  pro- 
lapsed on  account  of  loss  of  vitreous,  and  if  light  sense  is  destroyed, 
enucleation  of  the  eye  should  be  performed  at  once. 


2.  INJURIES  BY   BLUNT  INSTRUMENTS. 

Severe  pressure  on  the  eye  may  have  manifold  results.  Most  of 
these  results  I  had  a  chance  to  study  in  a  case  recently  treated  by 
me,  and  I  therefore  substitute  a  description  of  this  case  in  place  of 
a  systematic  relation  of  these  results.  A  workman  was  injured  by 
a  severe  blow  from  a  heavy  chain.  On  the  next  day  the  appear- 
ance was  as  follows :  there  was  a  gaping,  horizontal  skin  wound 
above  the  tear  sac  ;  the  eye  was  red,  weeping,  painful,  photophobic  ; 
there  was  a  small  conjunctival  wound  on  the  nasal  side  of  the  cor- 
nea, the  vicinity  being  ecchymosed ;  the  cornea,  particularly  below, 
was  both  diffused  and  linearly  opaque ;  the  anterior  chamber  deep ; 
the  pupil  dilated  and  motionless — iridoplegia  {p.  280)',  at  the  edge 
of  the  pupil  upward  and  inward  there  was  a  small  laceration  ;  with 
focal  illumination  the  lens  reflexes  were  not  visible,  but  the  gray 
lines  of  light  {p.  lod),  although  very  weak,  were  yet  evident  enough 
to  prove  the  presence  of  the  lens ;  the  fundus  was  invisible,  no  red 
reflex  being  obtainable  in  the  pupil.      F=  Fingers  at  0.5  m. 

After  several  days  the  cornea  cleared,  the  irritation  subsided,  and 
a  second  examination  showed  new  discoveries.  The  nasal  half  of  the 
iris  trembled  when  the  eye  was  moved — iridodotiesis ;  it  was  also 
translucent.  The  posterior  layer  of  the  iris  (the  pigment  layer)  had 
obviously  been  loosened  from  the  anterior ;  a  remnant  of  this  poste- 
rior layer  hung  in  the  pupil  like  a  loose  strand  upward  and  inward, 
but  behind  the  plane  of  the  iris.  The  lens  reflexes  were  now  visi- 
ble, the  lens  being  plainly  displaced  toward  the  temporal  side.  The 
lens  trembled  when  the  eye  was  moved. 

Some  weeks  later  the  eye  was  nearly,  though  not  quite,  free  from 
irritation,  the  lens  was  totally  opaque,  still  more  displaced  and  mov- 
able, and  at  the  same  time  so  revolved  on  its  perpendicular  axis 
that  its  anterior  surface  faced  toward  the  nose.  The  eye  was  blind 
beyond  mere  light  perception. 

There  quite  gradually  developed  other  disturbances,  such  as  at- 
tacks of  pain  and  increased  tension ;  at  the  same  time  peripheral 
light  projection  became  uncertain.     Rest  in  bed,  bandage  to  both 


414  INJURIES    TO    THE    EYEBALL. 

eyes,  and  eserin  seemed  to  remain  without  effect,  and  consequently 
the  extraction  of  the  lens  was  decided  on.  There  was,  of  course, 
prolapse  of  vitreous.  Healing  progressed  slowly ;  even  in  the  third 
week  after  the  operation  there  was  still  vitreous  in  the  somewhat 
contracted  wound.  In  spite  of  this,  douches  of  warm  sublimate 
solution  and  abundant  use  of  iodoform  powder  prevented  all  suppu- 
ration. In  the  fifth  week  the  wound  was  completely  healed,  but 
the  eye  was  still  somewhat  reddened  and  sensitive.  F=  Finger 
at  o.^  in.  Two  months  after  the  operation  the  eye  was  quiet,  but 
the  pupil  was  shut  off  by  a  membrane,  the  eye  blind  beyond  sensi- 
tiveness to  light. 

If  the  effect  of  a  dull  instrument  is  still  more  powerful  than  in  the 
above  case,  the  globe  may  burst ;  this  is  generally  associated  with 
hemorrhage  into  the  anterior  chamber  and  vitreous.  The  rent  in 
the  sclera  always  lies  parallel  to  the  corneal  margin  and  only  a  few 
millimeters  from  it,  opposite  the  spot  where  the  blow  was  received 
by  the  eye.  It  occurs  most  commonly  upward,  upward  and  in- 
ward, or  inward,  because  the  eye  is  least  protected  downward  and 
outward,  and  is  therefore  most  apt  to  be  struck  in  this  spot. 

The  process  of  rupture  may  be  conceived  as  follows :  The  instrument  causing  the 
blow  increases  the  tension  to  such  a  degree  that  the  fibers  of  the  sclera  yield  at  the  weak- 
est spot ;  the  rent  takes  place,  therefore,  from  within  outward.  The  fact  that  the  vicin- 
ity of  the  cornea  shows  itself  to  be  the  weakest  depends  probably  on  the  direction  of  the 
scleral  fibers,  since  the  thinnest  of  the  sclera  lies,  as  is  well  known,  somewhat  further 
back,  near  the  equator. 

The  elastic  conjunctiva  does  not  necessarily  tear  as  the  sclera 
bursts.  Through  the  opening  in  the  sclera  more  or  less  of  the  con- 
tents of  the  eye  prolapses — iris,  ciliary  body,  retina,  vitreous,  and 
sometimes  the  lens  itself.  If  the  injury  occurred  to  an  eye  already 
blinded  by  a  cataract,  it  may  really  be  of  advantage  in  encouraging 
the  expulsion  of  the  lens.  As  a  matter  of  fact,  cases  have  been 
observed  in  which  an  accidental  blow  removed  a  cataractous  lens 
and  thereby  restored  vision.  It  may  be  further  mentioned  that 
occasionally  the  whole  iris  is  torn  off  at  the  ciliary  margin  and 
escapes  from  the  eye  through  the  scleral  wound.  Rupture  of  the 
eye  is  caused  by  blows  from  the  horns  of  cattle,  by  falling  upon 
hard,  jagged  objects,  by  blows  from  the  fist,  canes,  or  feet,  and  by 
similar  accidents. 

The  diagnosis  of  a  scleral  rent  is  easy.  Either  the  iris  has  pro- 
lapsed into  the  wound,  in  which  case,  besides  the  wound  itself  and 


FOREIGN    BODIES    WITHIN   THE    EYE,  415 

the  iris  lying  in  it,  we  see  an  aperture  in  the  iris  corresponding  to 
the  location  of  the  rent ;  or  the  iris  has  not  prolapsed,  but  the  pupil 
is  at  least  dragged  in  the  direction  of  the  rent.  In  all  cases  the 
eyeball  has  lost  its  normal  tension  ;  it  is  soft. 

Prognosis  is  serious  ;    many  injured  eyes  become  phthisical. 

Treatment  consists  in  disinfection,  bandage,  and  rest  in  bed.  A 
prolapsed  iris  must  be  carefully  cut  ofif.  If  the  case  is  not  seen 
early,  the  iris  may  be  allowed  to  heal  in  the  wound,  the  prolapsed 
portion  being  destroyed  later  by  the  cautery. 


3.  FOREIGN  BODIES  WITHIN  THE  EYE. 

In  every  penetrating  injury  to  the  eye  the  question  must  be  asked 
whether  the  injuring  body — all  or  any  part  of  it — remains  within 
the  eye.  In  many  cases  this  may  be  unnecessary,  owing  to  the 
nature  of  the  accident  or  to  the  size  and  construction  of  the  object. 
In  other  cases  the  answer  is  easy,  since  the  foreign  body  may  be 
seen  with  the  naked  eye  or  by  means  of  focal  illumination  or  the 
ophthalmoscope,  either  in  the  anterior  chamber,  in  the  lens,  in  the 
vitreous,  or  on  the  posterior  wall ;  at  times  there  are  air  bubbles  on 
the  foreign  body,  recognizable  as  dark,  circular  areas  with  a  bright 
point  of  light  in  the  center.  In  other  cases  the  answer  is  very  dif- 
ficult, either  because  the  foreign  body  lies  in  a  recess  of  the  cham- 
ber, where  it  is  concealed  by  the  sclero-corneal  covering,  or  because 
of  the  rapid  opacification  of  the  lens,  or  of  hemorrhage  into  the 
vitreous,  or  of  inflammatory  exudate,  or  because  the  foreign  body 
is  located  so  near  the  ciliary  body  that  it  cannot  be  seen  by  the 
surgeon. 

In  such  difficult  cases  we  must  question  the  patient  as  to  the 
manner  of  the  injury,  examine  him  carefully,  and  take  all  the  cir- 
cumstances into  consideration.  There  must  always  be  suspicion 
^f  foreign  body  in  the  eye  if,  after  an  accident,  there  are  pain,  pho- 
tophobia, sensitiveness  to  pressure,  and  visual  disturbance  at  one 
time,  unexplainable  by  any  visible,  external  injury.  The  suspicion 
increases  to  certainty  if  we  can  find  changes  in  the  eye  which  un- 
mistakably indicate  a  canal  of  passage  for  a  foreign  body.  We 
must  then  examine  for  a  canal  of  entrance,  that  is,  for  a  wound  or 
scar  in  the  cornea  or  sclera.  The  size  of  this  canal  (it  is  often  very 
minute)  will  serve  as  a  hint  as  to  the  size  of  the  foreign  body,  at 


41 6  IN'JURIES   TO    THE    EYEBALL. 

least  in  two  dimensions.  It  may  be  incidentally  remarked  that  the 
smaller  the  canal  of  entrance,  the  greater  is  the  probability  that  the 
foreign  body  still  remains  within  the  eye.  We  must  next  look  for 
an  aperture  in  the  iris,  or  in  the  anterior  and  posterior  lens  capsule. 
If  this  last  can  be  demonstrated,  the  foreign  body  must  obviously 
rest  in  the  vitreous  or  fundus,  since  the  active  force  of  minute  parti- 
cles is  never  sufficient  to  penetrate  the  eye's  envelopes  a  second 
time.  Any  particle,  then,  remains  adherent  or  rebounds  and  sinks 
in  the  vitreous  to  the  bottom ;  in  such  cases  the  point  of  contact  in 
the  fundus  appears  as  a  bloody  or  as  a  white  spot. 

If  the  patient  is  not  examined  till  traumatic  cataract  has  already 
appeared,  and  the  vitreous  and  fundus  are  invisible,  the  physician 
must  content  himself  with  examination  of  the  field  of  vision,  which 
may  be  of  diagnostic  value  in  spite  of  the  opacity  of  the  lens.  Near 
the  foreign  body  the  retina  will  be  incapable  of  functionating  on 
account  of  the  atrophy  of  the  layer  of  rods  and  cones  with  the  ex- 
ternal granules,^  and  consequently  the  patient  will  not  perceive  the 
light  from  a  candle  when  it  is  brought  into  an  area  of  the  visual 
field  corresponding  to  the  neighborhood  of  the  injured  area  in  the 
retina. 

The  further  fate  of  the  eye — apart  from  the  mechanical  effect  of 
the  foreign  body — is  influenced  by  three  factors : — 

(i)  The  location  of  the  foreign  body; 

(2)  Its  chemical  nature;  and 

(3)  Whether  or  not  disease  germs  were  adherent  to  the  foreign 
body  during  the  injury. 

If  bacteria  were  introduced,  the  result  would  be  an  acute  abscess 
of  the  vitreous  passing  into  panophthalmitis  or  a  subacute  inflam- 
mation, according  to  the  number  and  pathological  character  of  these 
germs, — both  ending  in  destruction  and  atrophy  of  the  eye.  Only 
when  the  foreign  body  remains  in  the  anterior  chamber,  iris,  or 
lens,  is  our  art  able,  perhaps,  to  avoid  the  worst ;  if  germs  have 
reached  the  vitreous,  even  an  immediate  extraction  of  the  foreigrf 
body  will  not  help  to  save  the  eye. 

If  the  foreign  body  was  aseptic,  it  may  be  tolerated  in  the  lens  in 
spite  of  its  chemical  effect — the  result  being  traumatic  cataract,  but 
no  necessary  inflammation.  Cases  have  been  reported  in  which  the 
removal  of  the  lens  revealed  a  small  foreign  body,  the  presence  of 

^  At  least,  such  was  the  condition  in  a  case  under  my  observation. 


FOREIGN    BODIES    WITHIN    THE    EYE,  417 

which  was  quite  unsuspected  by  the  patient.  If  the  foreign  body- 
was  of  iron,  the  lens  becomes  a  diffused  yellow  on  account  of  the 
oxid  of  hydrogen  ;  or  there  are  rust-colored  points  near  the  foreign 
body.  Splinters  of  lustrous  metal  are  easy  to  recognize,  even 
through  an  opaque  body,  on  account  of  their  bright  reflex. 

In  the  vitreous  and  in  the  fundus  uncontaminated  bits  of  iron  or 
copper  may  retain  lodgment,  even  if  the  eye  at  first  was  more  or 
less  irritated.  Moreover,  even  in  these  favorable  circumstances 
changes  in  the  fundus  may  take  place  in  a  quiet  way,  especially  at 
the  macula  lutea,  and  vision  may  be  damaged.  It  must  be  finally 
mentioned  that  even  if  the  eye  remains  absolutely  quiet,  a  foreign 
body  is  a  veritable  sword  of  Damocles,  threatening  its  own  and  the 
other  eye,  too. 

The  ciliary  body  is  the  most  sensitive.  Foreign  bodies  chemic- 
ally unirritating  and  free  from  germs  may  here  produce  an  alarm- 
ing inflammation. 

From  what  has  been  said  it  is  evident  that  for  "  a  foreign  body 
within  the  eye  "  the  prognosis  is  extremely  unfavorable.  Left  to 
themselves  the  majority  of  cases  will  end  in  destruction  of  one  eye 
and  sympathetic  inflammation  of  the  other.  The  prognosis  is  bad 
even  with  proper  treatment.  An  analysis  by  Weidmann  of  the 
cases  under  Horner  and  Haab  showed  the  following  proportion  of 
losses : — 

If  the  foreign  body  is  in  the  anterior  chamber, o  per  cent. 

If  the  foreign  body  is  in  the  lens, 30  per  cent. 

If  the  foreign  body  is  in  the  vitreous , ji  per  cent. 

The  prognosis  is  particularly  bad  in  the  case  of  bits  of  iron  which 
are  chipped  off  old  and  fragile  instruments  used  when  working  in  a 
stony  soil  and  which  have  lodged  in  a  workman's  eye.  The  loss 
in  such  cases  is  about  8^  per  cent. 

Treatment.  Since  a  foreign  body  has  often  enough  been  seen 
to  find  lodgment  without  causing  harm,  it  is  not  necessary  that 
every  foreign  body  known  to  be  within  the  eye  must  be  without 
ceremony  attacked  by  an  operation.  It  is  better  to  weigh  the 
chances  for  healing  with  the  danger  of  the  operation.  When  the 
foreign  body  is  in  the  anterior  chamber  the  danger  of  the  operation 
is  slight;^  consequently  it  should  always  be  removed,  even  if  long, 
unirritating  residence  seems  to  confer  upon  it  the  rights  of  citizen- 

1  The  danger  may  be  shght,  but  not  the  operation  itself  I     This  operation,  with  that 
for  the  removal  of  bits  of  iron,  are  among  the  most  difficult  of  ophthalmic  surgery. 
27 


41 8  INJURIES    TO    THE    EYEBALL. 

ship.  A  lens  with  a  foreign  body  in  it  must  be  sooner  or  later 
removed  on  account  of  the  opacity,  the  foreign  body  being  then 
extracted  with  it.  The  treatment  of  foreign  body  in  the  vitreous 
depends  upon  the  material  composing  it.  If — as  is  the  case  in  the 
majority  of  such  injuries  (74  per  cent.,  Weidmann) — the  foreign 
body  is  of  iron,  the  hope  of  a  cure  must  be  abandoned  and  imme- 
diate resort  must  be  made  to  an  operation  which,  at  the  present 
day,  has  become  a  comparatively  easy  and  mild  one,  thanks  to  the 
use  of  the  electro-magnet.  If  the  foreign  body  was  a  splinter  of 
copper,  wood,  stone,  glass,  or  china,  an  inactive  treatment  may  be 
followed.  If  the  eye  does  not  calm  down  the  sclera  should  be 
incised,  and  through  it  an  attempt  made  to  seize  and  to  draw  out 
the  foreign  body  with  forceps.  If  this  is  unsuccessful  the  eye  must 
be  removed  to  avoid  danger  to  its  fellow. 

The  credit  of  introducing  the  magnet  into  ophthalmic  practice  belongs  to  Hirschberg. 
His  method  has  already  saved  innumerable  eyes  that  would  have  been  lost  without  the 
"  magnet  operation."     The  conditions  for  a  successful  result  are  :  — 

(i)  An  accurate  localization  of  the  foreign  body; 

(2)  Careful  antisepsis  ;  and 

(3)  An  absolutely  quiet  patient,  obtained  usually  by  chloroform  narcosis. 

The  approach  to  the  foreign  body  is  obtained  either  by  the  magnetic  sound,  that  is,  by 
pushing  through  the  canal  of  entrance  a  sound  armed  with  an  electromagnet  as  the  most 
usual  method — by  making  a  meridional  scleral  incision  at  the  equator  and  near  the  for- 
eign body,  through  this  introducing  into  the  vitreous  a  properly  shaped  probe  with  elec- 
tro-magnet attachment  which  must  be  brought  into  contact  with  the  foreign  body.  If  this 
can  be  done,  or  even  if  the  magnet  attachment  can  be  brought  near  enough  to  the  iron, 
the  latter  is  attracted  to  the  magnet  with  appreciable  force  and  sound. 

Haab  has  quite  recently  devised  a  new  magnet  operation.  It  depends  upon  the  fact 
discovered  by  Knies  that  by  simply  bringing  the  eye  into  the  vicinity  of  a  very  strong 
electro-magnet  a  bit  of  iron  can  be  drawn  from  the  vitreous  into  the  anterior  chamber, 
where  it  may  be  released  in  a  suitable  position  and  then  delivered  by  a  comparatively 
harmless  operation.  With  Haab's  electro-magnet  a  bit  of  iron  may  even  be  quite  with- 
drawn from  the  eye  in  the  tract  of  the  entrance  canal,  this  succeeding,  too,  as  I  have 
myself  observed,  even  when  the  entrance  canal  had  been  closed  for  several  days.  Of 
course  the  very  strongest  magnet  cannot  draw  a  bit  of  iron  through  the  intact  membranes 
of  the  eye.  It  should  be  remembered,  too,  that  the  iron  must  not  have  become  lodged 
in  the  sclera,  nor  be  retained  any  place  by  inflammatory  products. 


4.  SYMPATHETIC   INFLAMMATION  OF  THE   EYE. 

In  many  cases  of  injury  to  an  eye  the  history  of  the  trouble  does 
not  by  any  means  end  with  the  injury  to  or  even  loss  of  the  eye 
first  involved.     It  may  rather  begin  the  last  and  most  distressing 


SYMPATHETIC    INFLAMMATION    OF   THE    EYE.  4I9 

chapter,  the  passage  of  the  inflammation  to  the  other  eye,  sympa- 
thetic ophthalmia.  This  consists  of  a  plastic  cyclitis  or  iridocy- 
clochoroiditis  (/>.  2S6).  It  may  be  the  result  of  a  cyclitis  in  the 
other  eye  from  some  other  than  a  traumatic  origin,  but  such  cases 
are  rare.  Usually  it  is  an  injury  to  the  ciliary  body,  or  a  scleral 
wound  into  which  ciliary  body  and  iris  have  prolapsed  and  become 
incarcerated — but  especially  a  foreign  body  within  the  eye,  which 
causes  a  chronic  cyclitis  in  the  first  eye  and  a  subsequent  sympa- 
thetic inflammation  in  the  other. 

Other  diseases  also  may  arise  sympathetically,  particularly  iritis  serosa,  which  is  in  no 
way  so  serious  as  the  sympathetic  iridocyclitis  plastica.  There  have  also  been  reported 
cases  of  choroido-retinitis,  and  even  diseases  of  a  non-inflammatory  nature,  such  as  spasm 
of  the  orbicularis  and  optic-nerve  atrophy,  ascribed  to  "sympathy;"  whether  justly  so  or 
not  is  still  an  open  question. 

The  interval  of  time  between  the  injury  and  the  outbreak  of  the 
sympathetic  affection  is  quite  indefinite ;  it  usually  amounts  to  fo7ir 
to  eight  weeks,  but  cases  have  been  reported  sixteen  days  after,  and 
twenty-six  or  even  forty  (?)  years  after  ! 

The  disease  is  announced  by  premonitory  symptoms — moderate 
photophobia,  reduced  strength  for  near  work,  cloudy  vision.  Corre- 
sponding to  these  symptoms  there  are  a  mild  pericorneal  injection, 
moderate  opacity  of  the  aqueous,  and,  perhaps,  some  kind  of  poste- 
rior synechia ;  redness  of  the  disc  has  been  occasionally  observed. 
Gradually  these  signs  of  sympathetic  irritation  pass  into  those  of 
sympathetic  inflammation,  the  pain  and  cloudiness  increasing,  vis- 
ual acuity  decreasing.  The  internal  tension  is  changed,  being  at 
the  commencement  of  the  disease  noticeably  increased,  but  declin- 
ing below  normal  as  atrophy  begins. 

It  is  the  rule  that  after  varying  improvement  and  relapse  the 
pupil  is  displaced  by  adhesions,  the  iris  adheres  to  the  surface  of 
the  lens  capsule  (/.  28^),  the  vitreous  atrophies,  the  retina  pro- 
lapses, and  incurable  blindness  results.  A  cure  with  indistinct 
vision  may  be  obtained. 

The  nature  of  the  inflammation  is  not  yet  explained.  Mackenzie,  who  first  described 
sympathetic  inflammation,  supposed  that  it  passed  from  the  retina  of  the  injured  eye 
through  the  chiasma  to  the  retina  of  the  other  eye,  and  that  it  became  now  an  "iritis 
sympathetica."  This  old  and  rejected  view  has  been  recently  brought  again  into  promi- 
nence by  Leber  and  his  pupils.  Deutschmann  thinks  he  has  proved  that  germs  have 
traveled  from  the  injured  eye  backward  along  the  optic  nerve,  have  reversed  their  course 
at  the  chiasma,  have  ascended  in  the  lymph  channels  along  the  optic  nerve  of  the  other 
side,  and  thus  caused  the  direful  inflammation  in  the  second  eye.     This  doctrine,  so  clear 


420  INJURIES   TO    THE    EYEBALL. 

to  the  mere  reader,  has  found  many  doubters.  In  numerous  cases  of  sympathetically  dis- 
eased eyes,  examined  with  the  greatest  care,  no  germs  could  be  found.  Moreover,  it  has 
been  shown  that  all  sympathetic  inflammations  caused  by  him  with  bacteria  were  but  a 
local  manifestation  of  a  general  infection  of  the  entire  animal.  In  short,  Deutschmann's 
theory  has  not  as  yet  been  able  to  depose  the  hitherto  ruling  one  that  the  second  eye  was 
in  some  unknown  way  involved  through  the  ciliary  nerves.  To  be  sure,  we  have  no  con- 
vincing proof  of  this  theory,  but  a  series  of  clinical  facts  that  are  in  accord  witii  it  are  un- 
explainable  on  the  Mackenzie- Deutschmann  theory.  For  example,  the  fact  that  sympa- 
thetic irritation  may  develop  within  a  few  minutes,  and  that  a  foreign  body  on  the  cornea 
of  one  eye  may  arouse  photophobia  and  injection  of  the  uninjured  eye,  and  that  if  the 
tear  passage  of  one  eye  is  sounded  and  some  difficulty  is  met  in  reaching  the  meatus,  the 
eye  on  the  same  side  becomes  red,  while  the  other  eye  is  similarly,  although  to  a  less  ex- 
tent, affected.  A  second  indication  is  the  fact  that  the  inflammation  in  the  eye  sympathetic- 
ally affected  is  at  times  restricted  to  exactly  the  same  place  which  in  the  first  eye  was 
injured  or  sensitive  to  pressure.  A  third  indication,  observed  by  Mayweg  and  Schraidt- 
Rimpler,  is  the  fact  that  the  sympathetically  affected  eye  becomes  at  once  red  if  the  first 
eye  is  pressed  on.  And,  finally,  the  ciliary  nerves  would  seem  to  be  involved  by  the  fact 
drawn  from  experience,  that  atrophic  cicatrices  of  the  ciliary  body  and  atrophic  dejxjsits 
dragging  on  the  ciliary  body  are  particularly  prone  to  produce  sympathetic  inflammation, 
while  there  seems  little  to  be  feared  in  suppuration  of  the  eyeball,  in  spite  of  the  active 
bacteria  present,  presumably  because  the  ciliary  nerves  are  at  the  same  time  destroyed. 
Again,  atrophy  or  even  excision  of  the  optic  nerve  appears  to  offer  no  absolute  protection 
against  sympathetic  inflammation  so  long  as  any  of  the  ciliary  nerves  remain. 

Treatment  must  begin  by  interrupting  the  nervous  connection 
between  the  eye  first  involved  and  the  one  sympathetically  affected. 
This  can  be  accomplished  in  two  ways  : — 

(i)  By  cutting  the  ciliary  nerves.  This  was  proposed  originally 
by  V.  Graefe,  his  plan  being  to  sever  only  the  ciliary  nerves  sup- 
plied to  the  injured  area  and  then  only  from  within,  by  introducing 
a  knife  through  the  membranes  of  the  eye.  The  operation  has 
found  little  favor.  Snellen  has  found  more  followers ;  he  severed 
the  ciliary  nerves  before  their  entrance  into  the  eyeball  and  by  this 
means  overcame  pain  otherwise  unbearable.  In  operating  he  loos- 
ened an  eye  muscle,  passed  the  scissors  to  the  back  of  the  eye,  and 
cut  something  near  the  optic  nerve,  hoping  to  be  fortunate  enough 
to  include  the  proper  ciliary  nerves  in  the  incision. 

If  it  is  desired  to  sever  iall  the  ciliary  nerves  before  they  enter  the 
eye  the  optic  nerve  itself  must  be  cut  through — fienrotoinia  optico- 
ciliaris.  If  the  theory  of  inflammation  through  or  along  the  optic 
nerve  is  accepted,  a  mere  cut  through  the  optic  nerve  will  not  suf- 
fice, but  a  piece  of  it  must  be  excised — neurectomia  optic ocilictr is.  To 
perform  this  operation  the  internal  eye  muscle  must  be  detached, 
the  eyeball  rolled  energetically  outward,  the  scissors  glided  along 
the  sclera  till  it  reaches  the  optic  nerve,  which  is  then  severed  some 


SYMPATHETIC    INFLAMMATION    OF   THE    EYE.  42 1 

distance  away  from  the  eyeball.  It  is  now  possible  to  rotate  the 
eyeball  completely  so  that  the  posterior  pole  lies  exposed  in  the 
conjunctival  wound,  when  all  the  ciliary  nerves  entering  at  that 
place  can  be  cut.  The  optic  nerve  stump  still  attached  to  the  eye 
is  now  cut  off",  the  eye  replaced- in  its  normal  position,  and  muscle 
and  conjunctiva  sutured. 

These  different  methods  of  severing  the  ciliary  nerves  are  not  a 
trustworthy  protection  against  sympathetic  inflammation,  because 
all  the  ciliary  nerves  do  not  enter  the  eye  in  the  vicinity  of  the  optic 
nerve,  and  consequently  the  sensitiveness  of  the  eye  operated  on  is 
not  necessarily  destroyed  after  neurotomia  opticociliaris.  To  be 
quite  sure,  the  second  way  must  be  followed — enucleation. 

(2)  Enucleation  of  the  eye  first  affected  is  the  most  serviceable, 
prophylactic,  and  curative  remedy  for  sympathetic  inflammation. 
It  is  easy  to  understand  why  patients  should  decidedly  oppose  this 
mutilating  operation.  If  it  is  remembered,  too,»that  it  must,  if  pos- 
sible, be  performed  before  sympathetic  inflammation  begins,  if  the 
desired  result  is  to  be  obtained  and  that  every  iridocyclitis  does  not 
necessarily  lead  to  sympathetic  ophthalmia,  we  can  see  that  it  is 
one  of  the  most  difficult  tasks  of  the  ophthalmic  surgeon  to  decide 
when  and  when  not  to  resort  to  enucleation. 

The  following  rules  may  serve  as  guide: — 

(1)  If  the  first  eye  is  blind,  painful,  and  sensitive  to  pressure,  enucleation  is  to  be 
advised ;  it  is  to  be  urged,  if  the  patient  lives  away  from  a  surgeon,  and  thus  may  be  in 
danger  of  overlooking  the  beginning  of  sympathetic  inflammation.  If  the  patient  will 
not  consent,  he  should  be  told  to  seek  aid  at  the  first  sign  of  visual  disturbance  or  of 
inflammation  in  the  other  eye. 

(2)  If  the  first  eye  has  a  foreign  body,  is  painful  and  sensitive  to  pressure,  enucleation 
should  be  urged  even  if  the  eye  sees;  it  is  to  be  supposed,  of  course,  that  the  foreign 
body  cannot  be  removed  independently  (/.  ^77). 

(3)  If  sympathetic  irritation  or  even  inflammation  appears  in  the  second  eye  the  first 
must  be  enucleated  at  once.  If  the  first  eye  is  not  blind  but  still  retains  a  certain  visual 
acuity  and  is  to  some  extent  quiet,  both  patient  and  surgeon  will  hesitate  at  such  radical 
proceedings.  There  is,  however,  no  general  rule  for  such  a  case  ;  we  must  carefully 
compare  the  visual  acuity  of  the  first  eye  with  the  degree  of  irritation  in  the  second  ;  the 
more  there  remains  to  rescue  in  the  second  eye  the  greater  price  can  be  paid  by  the  first. 

Against  fully  developed  sympathetic  inflammation  the  physician 
is  powerless.  A  late  enucleation  is  usually  of  no  effect  and  the 
inunction  method  so  strongly  advised  by  Wecker  is  designated  by 
others  (Michel)  as  of  no  value.  Under  such  circumstances  we  must 
be  content  to  prevent  new  accidents,  to  lessen  pain  by  cocain,  warm 
compresses,  and  to  use  similar  symptomatic  remedies.     There  may 


422  INJURIES   TO    THE    EYEBALL. 

be  some  hope  for  the  subconjunctival  sublimate  injections  so  warmly 
recommended  by  French  and  Italian  confreres.  My  own  experi- 
ences have  not  been  encouraging.  Hydrargyrum  oxycyanatum 
has  been  warmly  praised  for  this  purpose  in  solution  of  /  .•  jooo. 
Whether  it  is  better  than  sublimate,  or  better  than  a  quite  indifferent 
solution  (the  physiological  chlorid  of  sodium  solution),  is  not  as 
yet  decided. 

Months  or  years  must  elapse  after  all  inflammatory  phenomena 
have  subsided  before  operations  such  as  iridectomy  or  cataract 
extraction  can  be  considered.  Noticeable  increase  in  tension  forms 
an  exception.  If  this  is  present  (at  the  beginning  of  sympathetic 
inflammation)  repeated  corneal  punctures  or  iridectomy  may  be 
performed  in  spite  of  the  inflammation. 

Enucleation  of  an  eye  is  mutilation.  The  patient  should,  there- 
fore, wear  an  artificial  eye  of  glass  or  celluloid,  which  often  is  so  like 
the  real  eye  that  even  the  nearest  associates  of  the  patient  may  not 
be  aware  of  the  deformity.  This  glass  eye  should  be  movable,  since 
the  muscles  ought  not  to  be  injured  in  enucleation.  The  tendons 
of  three  recti  muscles  are  separated  from  the  bulb,  the  eye  is  then 
turned  around  so  that  the  optic  nerve  can  be  reached  by  the  scis- 
sors, the  eyeball  is  luxated  and  the  three  remaining  eye  muscles 
cut  off.  These  six  eye  muscles  form,  after  healing,  a  flat  stump 
covered  with  conjunctiva,  which  follows  all  the  movements  of  the 
healthy  eye  and  transmits  them  to  the  artificial  eye  resting  upon 
this  stump.  If  the  movements  of  the  healthy  eye  are  extensive  the 
artificial  eye  lags  behind,  but  extensive  movements  are  usually  not 
resorted  to. 

To  aid  still  further  the  associated  movements  of  the  artificial  eye,  exenteratio  bu!bi  has 
been  substituted  for  enucleation.  This  consists  of  scooping  out  the  eye,  so  that  cornea, 
lens,  vitreous,  uvea,  and  retina  are  removed,  leaving  sclera  behind.  The  cavity  closes,  and 
a  stump,  consisting  of  scar-tissue,  sclera,  and  muscles,  remains.  The  stump  is  still  better 
if,  after  scooping  out  the  eye,  an  "  artificial  vitreous  "  of  glass  or  unoxidizable  metal  is 
introduced  and  allowed  to  heal  in  place.  Exenteration  with  the  use  of  an  artificial 
vitreous  is,  however,  so  new  that  at  present  it  is  still  doubtful  whether  the  cosmetic  effect 
is  not  purchased  at  the  cost  of  lessened  security  against  sympathetic  inflammation. 

An  artificial  eye  must  produce  no  discomfort,  and  the  stump 
particularly  must  be  kept  from  irritation.  Irritation  of  the  stump 
by  an  artificial  eye  has  led  to  sympathetic  inflammation  of  the 
other  eye.  At  night  the  artificial  eye  must  be  taken  out  and 
placed  in  water. 


APPENDIX.  423 


APPENDIX. 


The  question  is  often  raised  after  injuries  to  the  eye,  how  much 
the  injured  person  is  harmed  in  his  ability  to  earn  a  living.  Accord- 
ing to  the  effect  on  such  ability  is  the  compensation  to  be  paid  the 
injured  person  estimated.  If,  for  example,  the  injured  person  suf- 
fers a  loss  of  30  per  cent,  of  his  working  power,  and  has  therefore 
been  injured  30  per  cent,  in  his  wage-earning  capacity,  there  should 
be  paid  him  for  the  remainder  of  his  life  30  per  cent,  of  his  wages 
(income)  as  compensation. 

It  is  a  very  difficult  task  to  estimate  the  injury  to  wage-earning 
capacity,  because  there  must  be  taken  into  account  a  number  of 
factors  which  cannot  be  measured,  but  can  only  be  guessed  at. 
The  most  important  factor  is,  of  course,  the  amount  of  injury  to 
the  two  eyes.  It  must  be  mentioned  at  the  outset  that  a  mere  in- 
jury is  not  of  itself  a  justifiable  claim  for  compensation  ;  the  injury 
must  be  of  such  a  nature  as  to  hinder  the  patient  from  pursuing 
his  vocation.  It  stands  to  reason  that  an  injury  to  the  visual  organ 
may,  in  certain  vocations,  impair  the  wage-earning  capacity,  while 
the  same  injury  may  be  no  drawback  to  a  man  in  another  profes- 
sion. It  is,  therefore,  necessary  to  consider  also  the  optical  necessi- 
ties of  the  vocation  followed  by  the  injured  person.  Seamen,  rail- 
way employes,  mechanics,  and  those  in  technical  trades,  require 
greater  refinement  of  vision  than  do  day-laborers,  miners,  coopers, 
millers,  brewers,  drivers,  etc.  Even  workmen  of  the  first  group 
have  no  need  for  absolute  V  =  i  in  order  to  be  perfectly  capable 
in  their  vocation.  Again,  a  workman  of  the  second  group  with 
possible  F  =  ^—  is  completely  incapacitated,  while  a  workman  of 
the  first  group  is  incapacitated  with  F  no  lower  than  — ,  or  even  -v~. 

The  damage  done  to  the  eyes  themselves  is  a  product  of  three 
factors : — 

(1)  Visual  acuity,  (  F)  ^ 

(2)  Visual  field,  (G)  >■  and  any  impairment  to  them. 

(3)  Excursional  field,"~(-5 )  J 

Of  course,  visual  acuity  is  of  more  significance  for  the  wage-earn- 
ing capacity  "than  is  the  visual  field  or  the  excursional  field.  Con- 
sequently, each  one  of  these  three  factors  is  of  different  weight  in 
the  estimation  of  damage  done.  Finally,  account  must  be  taken 
of  a  fourth  (but  minor)  factor,  namely,  that  a  workman  finds  it  less 
easy  to  obtain  employment  after  it  is  known  or  recognized  that  his 


424 


APPENDIX. 


eyes  have  been  injured.  Many  factories  will  not  under  any  circum- 
stances employ  a  one-eyed  man,  although  with  his  one  eye  he  may 
be  able  to  satisfy  all  requirements  of  his  trade. 

The  problem  just  examined  has  been  mathematically  presented 
in  the  following  formula: — 

4    X     

E  ^v  s/  G'x  v/  ^  X  n/  ^. 

£  signifies  the  earning  capacity. 
F  signifies  the  visual  acuity. 
G  signifies  the  visual  field. 
B  signifies  the  excursional  field. 

A' signifies  the  competitive  element,  that  is,  the  capacity  for  obtaining  a  situation  in 
the  labor  market. 


All  these  values  are  either  equal  to  unity  {£  =  i),  that  is,  the 
injured  person  is  not  permanently  impaired;  or  he  is  impaired  in 
working  power,  and  then  the  values  all  become  real  fractions.  V 
is  the  most  important  factor  and  has  no  root  sign  ;  the  other  three 
quantities  are  represented  with  increasing  root  signs  proportionate 
to  their  decreasing  grade  (value),  since  the  root  of  a  real  fraction 
approaches  closer  to  unity  (that  is,  it  has  less  influence  on  the  pro- 
duct £)  the  higher  its  root  sign. 

By  means  of  this  formula  Magnus  has  worked  out  a  large  series 
of  cases  of  damage  through  injury.  From  his  results  I  present  in 
modified  tables  such  cases  as  are  of  most  common  occurrence. 

Loss  of  earning  power,  one  eye  being  damaged,  the  other 
unaffected : — 

Loss  OF  Working  Power 

In  vocations 
V.  OF  THE   D.\MAGED   EyE. 

1:0.75 

0.7 

0.6 

0-5       r 
0.4 

03 

0.2 

0.15 

Less  than  0.15 
Less  than  0.05 
o. 


In  vocations  demanding 
great   technical  skill  and 
hence  acute  vision. 

In  vocations 
need  0/  acute 

iDith  but  slight 
vision . 

0.    per  cent. 

O- 

per  cent. 

0.4 

0. 

1.3        " 

0. 

2.3        " 

0. 

3-4        " 

1.2 

4.6       " 

2-5 

6.0       " 

4.0 

6.7        " 

4.8 

15-6       " 

i?6 

31. 

27. 

APPENDIX. 


425 


Loss  of  earning  power,  one  eye  being  blind,  the  other  damaged 
in  visual  acuity.     Technical  iwcations  dema7iding  acnte  vision  : — 


V. 

0.7 
0.6 

05 
0.4 

0.3 
0.2 
0.1 


Loss  OF  Earning  Power. 
37.8  per  cent. 
51.0       " 
63.8      " 

75.8  " 

86.9  " 
96.5      - 

lOO.O        " 


LOSS  OF  EARNING   POWER    IF  THE  VISUAL  ACUITY  IN    BOTH  EYES 

HAS  SUFFERED;    TECHNICAL  VOCATIONS  DEMANDING 

ACUTE  VISION:  — 


^\^    V.  of  one 
V.  or\      eve. 

theotherX/^^      I  to  0.75  |'     0.6 
eye.     J      \x,^j 

0.4 

0.2 

I  to  0.75 

0 

1-3             3-4 

i 

6.0 

s 

'£ 

m 
0 
0 

0.6 

'-3 

27.1 

29.0 

313 

0.4 

3-4 

29.0 

61.8 

637 

0.2 

6.0 

313            637 

93-5 

DISTURBANCES  IN  THE  MOVEMENTS  OF  THE 

EYES.i 

I.  STRABISMUS  PARALYTICUS  (Paralytic  Squint). 

I.  DIAGNOSTIC  SIGNS. 
Those  who  seek  aid  for  paralytic  squint  are  nearly  always  adults. 
They  complain,  as  a  rule,  of  vertigo  and  diplopia  (double  vision). 

^  To  understand  this  section,  an  accurate  knowledge  of,  or  repeated  reference  to, 
Section  v.,/.  70  et  seq.,  is  indispensable. 


426 


DISTURBANCES    IN    THE    MOVEMENTS    OF   THE    EYES. 


The  vertigo  is  the  result  of  a  false  projection  (/.  77),  and  is  con- 
sequently present  only  when  using  the  diseased  eye.  The  double 
vision  is  the  result  of  the  squinting  position  (/>.  72),  and,  like  this 
position,  is  present  only  in  those  areas  of  the  visual  field  to  reach 
which  the  paralyzed  muscle  must  be  called  into  play  (/.  Sj). 

In  many  cases  double  vision  is  rather  masked.  The  patient  complains  that  objects 
appear  indistinct  in  some  positions,  and  that  at  such  times  he  has  a  feeling  of  discomfort. 
This  depends  upon  masked  diplopia,  and  implies  that  the  patient  has  been  at  an  earlier 
period  accustomed  to  give  particular  attention  to  the  images  of  only  one  eye,  and  that,  con- 
sequently, the  double  images  do  not  make  a  proper  impression  on  his  consciousness.  By 
using  a  colored  glass  it  is  generally  easy  to  change  such  a  masked  diplopia  into  clearly 
perceived  double  images  (/.  Sy). 

The  complaints  of  the  patient  differ,  according  to  whether  the  loss  of  muscular  power 
is  complete  (^paralysis)  or  incomplete  [paresis) ;   and  according  to  the  importance  of  the 


Jtsd.  jup. 


>mesap.~ 


Jieci.  ext. 


-  ONi^ti.  supin 


Xeft.int. 


~-£>Mi^u^.  in/er 


Fig.  151. — The  Eye  IMuscles  seen  from  in  Front.     {After  Merkel.) 

diseased  muscle  for  covering  particular  areas  of  the  visual  field.  In  reading  and  writing, 
for  example,  paralysis  of  a  muscle  involved  in  movement  to  the  right  (rectus  internus  of 
the  left  or  rectus  externus  of  the  right  eye)  causes  far  more  disturbance  than  paralysis  of 
the  muscle  involved  in  movement  to  the  left;  in  going  up  stairs  (in  all  motion,  in  fact), 
paralysis  of  the  depressor  muscles  (recti  inferiores  and  obliqui  superiores)  causes  more 
disturbance  than  paralysis  of  the  elevators  (recti  superiores  and  obliqui  inferiores). 

Often,  in  looking  at  a  patient  making  such  complaints,  an  oblique 
position  of  the  head  may  be  noticed.  The  patient  soon  learns, 
when  looking  at  objects  in  front  of  him,  to  use  a  position  of  the  eyes 
in  which  as  little  demand  as  possible  is  made  upon  the  paralyzed 
muscle.  If,  for  example,  the  left  rectus  externus  is  paralyzed,  the 
patient  turns  his  head  toward  the  left;  his  eyes  must,  therefore, 
make  a  compensatory  movement  toward  the  right  in  order  to  look 


DIAGNOSTIC   SIGNS.  ^  42/ 

straight  ahead.  If  a  superior  rectus  is  paralyzed,  the  patient  throws 
his  head  back  in  order  to  bring  his  eyes  under  the  control  of  the 
depressor  muscles,  the  recti  inferiores  and  obliqui  superiores.  These 
positions  of  the  head  are  so  significant  that  of  themselves  they  may 
betray  the  condition  to  the  experienced  observer.  A  long  con- 
tinuance in  such  positions  of  the  head  may  cause  contractures  of 
the  neck  and  back  muscles.  Cases  are  reported  in  which  stiff  neck 
(torticollis)  has  been  treated  in  vain,  until  the  cause  for  the  stiff  neck 
was  discovered  to  be  an  eye-muscle  paralysis. 

In  making  a  diagnosis  it  is  of  the  greatest  importance  to  be 
sure  that  the  double  vision  is  not  confined  to  one  eye  (/.  JS^)  '■>  ^^ 
such  a  case,  of  course,  double  vision  remains  when  the  other  eye 
is  closed.  It  must  be  further  tested  to  see  that  the  disturbance  in 
movement  does  not  depend  on  some  simple  external  cause,  as  a 
pterygium,  a  collection  of  pus  or  blood,  or  some  new  growth  be- 
hind the  eyeball. 

If  such  causes  can  be  excluded  we  may  assume  the  squint  to  be 
paralytic  and  try  to  find  out  which  is  the  paralyzed  eye.  In  pro- 
nounced cases  a  simple  test  of  the  excursion  of  movement  in  each 
eye  will  suffice  {p.  8j),  since  the  recognition  of  a  lapse  in  either 
eye  proves  that  this  eye  is  diseased.  But  in  other  cases  this  method 
of  examination  gives  no  exact  results, — either  because  the  paralysis 
is  not  complete,  and  consequently  the  lapse  of  movement  is  too 
small,  or  because  the  paralysis  involves  muscles,  the  obliqui,  for 
example,  which  are  of  minor  importance  in  performing  the  visual 
excursion.  In  such  cases  the  position  of  the  other  eye  remaining 
covered  must  be  compared  with  the  position  of  the  fixing  eye.  If, 
for  example,  the  rectus  externus  of  the  left  eye  is  half  paralyzed  and 
the  eye  in  consequence  is  unable,  even  with  the  greatest  effort,  to 
follow  to  the  normal  limit  of  its  excursion  a  finger  moved  in  front 
of  it  toward  the  left,  the  right  and  covered  eye  will  pass  into  the 
position  of  extreme  adduction  and  its  visual  line  will  finally  aim 
toward  the  left  of  the  finger  followed  by  the  left  eye.  This  is  a 
proof  that  the  same  impulse  of  the  will  affected  the  externus  of  the 
left  eye  less  than  it  did  the  internus  of  the  right  eye,  and  that, 
therefore,  the  left  is  the  eye  paralyzed.  There  results  from  this  the 
general  rule  that  "  the  more  squinting  eye  is  the  healthy  eye," 
because  when  the  diseased  eye  looks  toward  the  side  of  the  para- 
lyzed muscle,  the  healthy  eye  passes  into  the  deviation  of  squint 
(a  ^S))  which  is  greater  than  the  primary  deviation  which  the  dis- 


428  DISTURBANCES    IN    THE    MOVEMENTS    OF    THE    EYES. 

eased  eye  assumes  if  the  healthy  eye  fixes.  A  further  sign  is  given 
by  the  fact  that  the  vertigo  ceases  when  the  diseased  eye  is  closed. 
This  sign  may  have  been  noticed  by  the  patient,  who  is  accus- 
tomed, therefore,  to  squeeze  his  bad  eye  shut.  To  be  sure  this  is 
not  always  the  case,  for  it  may  happen  that  the  diseased  eye  pos- 
sesses the  better  visual  acuity,  in  which  case  the  patient  neglects 
the  unparalyzed  eye  and  fixes  with  the  paralyzed  one,  attempting, 
meanwhile,  to  protect  himself  against  false  projection  of  images  and 
the  vertigo  accompanying  it  by  moving  his  head.  If  these  meth- 
ods still  leave  the  diagnosis  uncertain,  we  must  resort  to  the  double 
image  test  as  explained  by  the  rules  given  on  pp.  Sy,  ^jj. 

The  diagnosis  must  now  be  extended  to  the  detection  of  the 
paralyzed  muscle  or  set  of  muscles.  This  task,  so  easy  in  some 
cases,  may  in  other  cases  be  one  of  the  most  difficult  in  the  whole 
extent  of  ophthalmology  or  neurology.  In  one  instance  several 
muscles  of  one  or  of  both  eyes  may  be  paralyzed,  in  another  in- 
stance the  paralysis  may  attack  eyes  in  which  the  muscle  balance  has 
already  been  previously  disturbed.  Finally — a  frequent  result,  too — 
when  the  paralysis  of  one  muscle  is  of  long  standing,  there  develops 
a  secondary  contraction  of  its  antagonist.  It  is  evident  that  to  keep 
all  these  circumstances  clear  in  one's  mind  must  be  an  extremely 
difficult  task.     We  can  now  examine  the  simplest  cases,  namely: — 

(a)  Isolated  paralysis  of  a  rectus  extern  us  ; 

{b)  Isolated  paralysis  of  an  obliquus  superior; 

{c)  Paralysis  of  the  muscle  group  supplied  by  the  nervus  oculo- 
motorius. 

These  three  cases  are  the  commonest  and  the  most  practically 
important.  The  reason  for  this  will  be  explained  in  the  discussion 
of  causes. 

In  A.  Graefe's  rich  experience  of  eye-muscle  paralyses  the  following  were  the  usual 
percentages  in  each  lOO  cases  : — 

32  per  cent,  isolated  paralysis  of  a  rectus  externus ; 
16  per  cent,  isolated  paralysis  of  an  obliquus  superior; 
8  per  cent,  isolated  paralysis  of  one  of  the  four  remaining  muscles  ; 
44  per  cent,  combined  paralysis  of  all  these  four  remaining  muscles  in  one  or 
both  eyes. 

{a)  Paralysis  of  the  Left  Rectus  Externus  J — The  patient 
holds  his  head  to  the  left.     If  his  right  eye  is  now  closed  and  if  he 

1  For  simplicity's  sake  I  shall  describe  a  left-sided  paralysis  in  each  instance.  The 
student  can  make  out  a  right-sided  paralysis  by  changing  the  words  in  the  text. 


PARALYSIS    OF   THE    LEFT    RECTUS    EXTERNUS. 


429 


is  asked  to  walk  rapidly  about  the  room,  he  will  grow  dizzy  enough 
to  fall.  If  a  finger  is  then  held  toward  the  right/  and  if  he  is  asked 
to  fix  this  finger,  both  eyes  take  the  proper  position  with  refer- 
ence to  it ;  but  if  the  finger  is  now  moved  over  the  median  line  of 
the  patient  toward  the  left,  his  left  eye  remains  still,  or  moves  only 
in  a  jerky  manner,  with  alternate  rotatory  movements  in  opposite 
directions,  upward  outward  and  downward  outward,  this  being  the 
result  of  the  contraction  of  the  two  obliqui,  which  are  vainly  endeav- 
oring to  act  in  place  of  the  paralyzed  externus.  The  farther  the 
finger  passes  to  the  left,  the  more  evident  is  this  lagging  behind  of 
the  left  eye  and  the  accompanying  position  of  convergence  caused 
by  it. 

Fig.  1^2  illustrates  the  position  of  the  double  images  for  nine 


l^KoMl  te»ti!/t 

^/xyanir 

C^fmiMs&eA^n^ 

toOuUn 

I 
1 

ftrat^aAta£ 

totheni^ht 

<lo**mi*>a/t£i 

{aSfi£rt^tiMmmwi& 

Fig.  152. — Double  Images  in  Paralysis  of  The  Left  Rectus  Externus. 

A  Red  mark  is  the  image  of  the  ^ight  eye  ;  a  bZ.ue  mark  that  of  the  Aeft  eye.     The  words  on  the  chart 

indicate  the  areas  of  the  field  of  vision. 

different  areas  of  the  visual  field  ;  they  appear  as  they  would  to  the 
reader  if  his  left  rectus  externus  were  paralyzed.  It  will  be  seen 
that  the  line  separating  the  field  into  two  parts — one  containing 
double  images,  the  other  a  single  image — is  not  perpendicular  but 
runs  from  above  and  to  the  left  downward  and  to  the  right.  This 
depends  on  the  fact  that,  when  looking  upward,  convergence  is  phy- 
siologically favored,  and  when  looking  downward,  divergence  is  so 
favored.  This  fact  is  explained  by  the  habit  of  looking  at  distant 
objects  with  the  eyes  somewhat  raised,  but  at  near  objects,  the 
book,  for  example,  with  the  eyes  lowered.  It  may  be  added  that 
occasionally  a  moderate  obliquity  and  inequality  of  elevation  in 
the  two  images  is  admitted. 


^  Right  and  left  always  refer  to  the  patient. 


430 


DISTURBANCES    IN    THE    MOVEMENTS    OF    THE    EYES. 


If  the  paralysis  is  incomplete,  the  dizziness  may  be  quite  pre- 
vented by  the  patient's  turning  his  head  to  the  left.  The  left  eye 
follows  the  finger  more  or  less  toward  the  left  past  the  median  line 
of  the  body,  but  the  external  edge  of  the  cornea  cannot  be  brought 
to  the  outer  canthus.  If  this  lapse  is  too  small  to  establish  a  diag- 
nosis, the  physician  must  observe  the  secondary  deviation  of  the 
healthy  eye,  which  seemingly  exaggerates  the  disturbances  of 
movement  in  the  diseased  eye.  The  line  separating  the  visual  field 
into  parts  of  single  and  double  images  lies  rather  more  to  the 
left  than  in  Fig.  1^2 ;  in  the  minimum  degree  of  paralysis  the 
double  images  may  quite  escape  notice,  since  by  an  unequal  inner- 
vation of  the  two  muscles  involved  in  movement  toward  the  left 
(stronger  impulse  to  the  left  externus,  weaker  to  the  right  intern  us) 


Fig.  153.— Double  Images  in  Paralysis  of  the  Left  Obliquus  Extbrnus. 
A  i?ed  mark  is  the  image  of  the  iJight  eye  ;  a  bZue  mark  that  of  the  Z,eft  eye.     The  words  on  the  chart 
indicate  the  areas  of  the  field  of  vision. 


a  fusion  of  the  images  may  be  accomplished.  The  desire  to  fuse, 
and  the  range  of  fusion,  differ  in  different  cases.  If  we  wish  to 
make  the  position  of  the  eyes  independent  of  fusion,  we  should  use 
a  prism,  base  downward  or  upward,  held  before  one  eye.  Fusion 
will  now  be  impossible,  and  a  latent  separation  of  the  images  will 
be  easily  discovered. 

{S)  Paralysis  of  the  Left  Obliquus  Superior. — The  patient 
turns  his  head  downward  toward  the  right,  that  is,  about  an  axis 
running  in  the  same  direction  as  the  line  {Fig.  i^j)  separating  the 
field  into  two  parts,  from  below  to  the  left  upward  to  the  right.  He 
thus  brings  the  upper  left  part  of  the  visual  field  immediately  to 
the  front,  this  part  being  usually  but  little  used.  This  position  of 
the  head  is  therefore  particularly  noticeable,  and  is  diagnostic  of 
paralysis  of  the  trochlearis. 


PARALYSIS    OF   THE    LEFT    OBLIOUUS    SUPERIOR.  43 1 

The  restriction  in  movement  is  much  smaller  than  in  paralysis  of 
the  rectus.  It  is  best  demonstrated,  however,  by  moving  the  finger 
downward  and  to  the  right,  into  the  lower  right  ninth  of  the  visual 
field;  in  this  case  the  eye  cannot  follow  the  finger;  the  eye  is  too 
high.  To  understand  this,  the  student  should  refer  to  Fig.  2y  {p.  y8). 
It  will  be  noticed  that  if  the  left  e3^e  is  rotated  sufficiently  to  the 
right,  the  horizontal  axis,  that  is,  the  axis  of  rotation  for  depression, 
forms  a  right  angle  with  the  direction  of  traction  of  the  tendon  of 
the  superior  oblique  muscle  ;  consequently  to  effect  a  sufficient 
turn  to  the  right  in  the  left  eye,  the  superior  muscle  must  become 
a  pure  depressor.  Since  the  lower  right  area  of  the  visual  field 
can  be  reached  only  by  means  of  the  left  superior  oblique,  a  paraly- 
sis of  this  muscle  must  cause  the  left  eye  to  remain  the  furthest 
away  from  this  position.  The  condition  is  reversed  in  looking 
downward  to  the  left.  In  this  direction  the  rotatory  muscle  be- 
comes purely  a  muscle  for  circular  rotation,  and  consequently  a 
paralysis  of  it  has  no  influence  upon  such  available  positions  of 
the  visual  lines. 

Double  images  are  of  particular  importance  in  overcoming  the 
difficulties  encountered  in  perceiving  and  measuring  any  restric- 
tions in  movement.  They  are  illustrated  in  Fig.  ijjj,  and  corre- 
spond to  the  position  of  the  eyes  in  the  diagram.  In  looking  to 
the  right  there  is  seen  a  difference  in  elevation,  which  increases  as 
the  candle  (the  test  fixation-point)  is  lowered.  In  looking  down- 
ward to  the  left  there  is  seen  the  greatest  obliquity,  an  evidence  of 
rotatory  movement  exaggerated  in  an  eye  in  which  the  inferior 
oblique  has  lost  its  antagonist.  The  image  is  moderately  depressed 
and  removed  to  the  side.  In  looking  straight  ahead  or  directly 
downward,  there  is  obliquity,  depression,  and  removal  to  the  side, 
the  last  condition  allowing  the  recognition  of  homonymous  double 
images.  Since  the  superior  oblique  muscle  causes  abduction  as 
well  as  depression  and  rotation,  its  paralysis  must  result  in  adduc- 
tion or  a  position  of  convergence. 

Many  patients  assert  voluntarily  that  the  lower  image — belonging  to  the  diseased  eye, 
therefore, — appears  nearer  and,  perhaps,  smaller  than  the  image  of  the  healthy  eye.  The 
smallness  of  the  image  is  to  be  taken  as  the  result  of  its  apparent  nearness.  We  may 
decide  that  two  retinal  images  of  the  same  size  belong  to  two  objects  of  different  sizes,  in 
case  we  choose,  for  one  reason  or  another,  objects  at  different  distances  {cornpm-e p.  288). 
The  apparent  nearness  of  the  image  is  itself  not  yet  satisfactorily  explained,  and  the  views 
of  various  authors  are  not  harmonious.  Two  facts  in  this  connection  may  be  mentioned  : 
first,  that  the  nearness  of  the  lower  image  is  not  apparent  in  trochlear  paralysis  alone,  but 


432  DISTURBANCES    IN    THE    MOVEMENTS    OF    THE    EYES. 

may  be  produced  artificially  in  the  higher  image  by  means  of  a  prism,  or  displacement  of 
the  eye  with  the  finger;  and,  second,  that  the  surroundings  of  the  double  images  have  a 
distinct  influence  on  the  lower  image.  For  example,  a  ball  hanging  on  a  thread  appears 
as  two  images  exactly  over  each  other,  while  the  same  ball  on  a  plate  appears  as  two 
images,  one  in  front  of  the  other.      i^N'ngePs  experiment.) 

If  the  paralysis  is  incomplete,  the  obliquity  of  the  images  or  the 
restriction  in  movement  will  not  be  evident,  or  will  be  demonstra- 
ble only  in  the  lower  right  corner  of  the  visual  field.  The  diag- 
nosis depends  then  exclusively  upon  the  double  images,  that  is, 
upon  double  vision,  with  predominant  elevation  to  the  right  below, 
and  with  predominant  obliquity  to  the  left  below. 

{c)  Paralysis  of  the  Muscle  Group  supplied  by  the  left  Ner- 
vus  Oculomotorius. — Rcchis  superior  and  inferior,  rectus  inter- 
nus  and  obliquus  inferior.  The  recognition  of  this  pathological 
condition  is  easy,  since  a  complete  paralysis  of  so  many  muscles 
must  produce  appreciable  disturbance.  The  position  of  the  two  eyes 
when  looking  straight  ahead  is  one  of  divergence.  The  movement 
of  the  diseased  eye  inward,  upward  and  downward,  is  prevented  ; 
movement  outward  (to  the  left)  and  outward  downward  (downward 
to  the  left)  is  still  possible  with  the  rectus  externus  and  obliquus 
superior.  Consequently,  divergence  increases  decidedly  when  look- 
ing toward  the  right.  When  the  eyes  are  directed  upward  there  is 
depression — when  downward,  elevation — of  the  diseased  (left)  eye. 

In  an  incomplete  paralysis,  on  the  other  hand,  the  visible  defects 
of  movement  are  less  apparent,  and  the  diagnosis  must  be  made 
from  the  location  of  the  double  images.  As  Fig.  75^  shows,  these 
are  crossed ;  in  looking  upward  the  image  of  the  left  eye  is  higher, 
in  looking  downward,  lower,  than  the  image  of  the  right  eye ;  but 
the  difference  in  elevation  is  less  in  looking  downward  than  in  look- 
ing upward,  because  one  of  the  muscles  concerned  in  depression, 
the  superior  oblique,  is  not  affected.  The  distance  between  the  two 
images  increases  in  looking  toward  the  right,  and  disappears  in  a 
small  area  of  the  visual  field  lying  to  the  left  and  below  when  look- 
ing in  that  direction.  There  is  also  obliquity  of  one  of  the  images, 
but  this  is  usually  noticed  by  the  patient  only  when  the  images  are 
close  together,  as  in  looking  directly  outward  or  downward,  or  to- 
ward the  left  downward. 

In  the  majority  of  cases,  even  in  those  of  hemiparalysis,  the 
diagnosis  is  essentially  simplified  through  the  involvement  of  other 
muscles.     To  make  this  clear  we  must  understand  and  apply  what 


SECONDARY    CONTRACTURES. 


433 


is  said  further  on  concerning  the  nature  of  eye-muscle  paralysis, — 
that  in  the  great  majority  of  cases  the  condition  is  of  disease  of  the 
nerves  rather  than  of  the  muscles.  Since  the  nervus  oculomo- 
torius  supplies  a  lid  muscle,  the  levator  palpebrae  superioris,  and 
two  internal  eye  muscles,  the  sphincter  iridis  and  the  musculus 
ciliaris,  as  well  as  the  four  external  eye  muscles  already  mentioned, 
the  typical  pathological  picture  is  the  following:  The  upper  lid 
droops  and  its  horizontal  folds  are  obliterated  ;  if  the  lid  is  elevated, 
the  pupil  of  the  diseased  eye  is  found  to  be  moderately  dilated  and 
irresponsive  to  any  of  the  three  methods  of  stimulation  (/.  26g) — 
it  is  rigid.  The  power  of  accommodation  is  lost,  causing  more  or 
less  disturbance  of  vision  according-  to   the  refractive  condition. 


W?i£nlook/nA 


Fig.  154. — Paralysis  of  the  Left  Oculomotorius. 

A  R^A  mark  is  the  image  of  the  /fight  eye ;  a  biue   mark  that  of  the  /.eft  eye.     The  black   mark  is  the 

single  image  for  the  two  eyes. 


There    is    some   exophthalmos,  because   three  of  the    four   recti 
muscles  which  draw  the  eye  backward  are  paralyzed. 

The  general  rule  for  determining  a  paralyzed  muscle  may  be  deduced  from  what  has 
been  said  :  place  a  candle  in  each  of  the  above-mentioned  nine  areas  of  the  visual  field 
and  ask  the  patient,  his  sound  eye  being  particularized  by  having  a  red  glass  disk  in  front 
of  it,  to  fix  this  candle  without  turning  his  head.  The  patient's  responses  as  to  the  loca- 
tion of  the  double  images  are  to  be  noted  by  a  red  and  a  blue  pencil.  From  a  diagram 
thus  made  it  is  not  difficult  to  form  a  diagnosis,  provided  that  the  action  of  each  muscle 
(/•  7^)  'S  known  and  that  the  case  is  a  fresh  and  uncomplicated  one.  But  since  there 
are  some  patients  in  whom  the  distinct  type  of  an  eye-muscle  paralysis  is  obscured,  the 
most  important  complications  need  a  short  analysis. 

(a)  Secondary  Contractures. — If  the  paralysis  has  lasted  some  time, the  antagonist  of 

the  paralyzed  muscle  is  accustomed  to  drag  the  eye  more  and  more  to  its  own  side,  even 

in  a  condition  of  rest,  and  "  secondary  contracture  "  is  the  result.     Consequently,  squint 

and  diplopia  are  present  even  in  those  areas  of  the  visual  field  in  which  the  paralyzed 

28 


434  DISTURBANCES    IN    THE    MOVEMENTS   OF   THE    EYES. 

muscle  is  inactive.  If,  for  example,  in  theabovecase  of  paralysis  of  the  left  rectus  externus, 
a  contracture  of  the  left  rectus  internus  had  supervened,  the  line  separating  the  visual  field 
into  its  two  parts  of  areas  with  and  without  double  images  would  lie  farther  to  the  right 
or,  perhaps,  would  fall  quite  at  the  edge  of  the  visual  field ;  and  in  the  left  part  of  the 
field  the  double  images  would  be  wider  apart  than  before.  The  differential  sign  in  the 
association  of  paralysis  of  the  left  externus  with  contracture  of  the  left  internus  depends 
upon  the  fact  that  in  looking  toward  the  left  the  double  images  flit  apart  in  the  left  half 
of  the  visual  field,  while  in  looking  toward  the  right  the  same  distance  is  maintained  in 
the  right  half  of  the  visual  field. 

(,3)  Preexisting  Disturbance  in  Equilibrium  of  the  Muscles. — If  a  patient  suf- 
fering from  latent  squint  (/.  8g)  is  attacked  by  paralysis  in  the  muscles  of  one  eye,  the 
latent  squint  will  change  into  manifest  squint  for  that  part  of  the  visual  field  in  which 
binocular  fusion  is  now  rendered  impossible  on  account  of  this  muscle  paralysis.  In  this 
case  the  location  of  the  double  images  is  influenced  both  by  the  paralysis  and  by  the 
latent  squint.  P'or  example,  if  a  weakness  of  both  internal  recti  (lateral  divergent  squint) 
is  associated  with  paralysis  of  a  depressor  muscle,  there  will  be  crossed  double  images  in 
looking  downward,  irrespective  of  whether  it  is  the  inferior  rectus  (with  its  adduction)  or 
the  superior  oblique  (with  its  abduction)  which  is  paralyzed.  For  the  slight  convergence 
that  may  be  expected  as  the  result  of  paralysis  of  the  oblique  as  abductor  will  be  more 
than  neutralized  by  the  preexisting  latent,  divergent  squint  now  become  manifest. 

How  can  we  distinguish  in  such  a  case  whether  the  rectus  inferior  or  the  obliquus 
superior  is  paralyzed  ?  How  can  we  be  sure  whether  actual  latent  squint  is  present  ? 
The  first  question  is  answered  by  the  statement  of  the  fact  that  the  mode  of  action  of  an 
inferior  rectus  and  of  a  superior  oblique  is  subjected  to  exactly  opposite  changes  in  adduc- 
tion or  abduction  of  the  eye.  {See  Fig.  2j,  p.  /<?).  By  a  definite  movement  of  the 
eyes  toward  the  right  the  rectus  inferior  of  the  left  eye  becomes  a  pure  muscle  of  rotation 
and  the  obliquus  superior  a  pure  depressor ;  by  a  definite  movement  of  the  eyes  toward 
the  left  the  rectus  inferior  becomes  a  pure  depressor  and  the  superior  oblique  a  pure 
muscle  of  rotation.  Consequently,  if  the  candle  is  moved  to  the  right  and  then  down- 
ward, the  difference  in  elevation  between  the  double  images  increases  when  the  obliquus 
superior  is  paralyzed,  but  decreases  if  the  rectus  inferior  is  paralyzed.  No  attention  need 
be  paid  to  the  obliquity  of  the  double  images,  since  the  statements  of  the  patient  are  quite 
untrustworthy  and  since  the  elevation  of  the  images  will  differentiate  as  completely  as 
will  be  necessary. 

The  second  question  is  answered  by  using  a  prism  before  one  of  the  eyes,  base  down- 
ward or  upward.  By  this  means  the  desire  to  suppress  the  latent,  divergent  squint  is 
overcome  for  the  upper  half  of  the  visual  field,  and  the  double  images  will,  therefore, 
appear  in  this  upper  half  as  well,  but  obviously  without  difference  in  elevation. 

Paralysis  of  all  the  external  eye  muscles  is  called,  since  Mauth- 
ner,  ophthalmoplegia  exterior,  while  paralysis  of  the  sphincter  pupil- 
lae  and  the  ciliary  muscle  is  termed  ophthalmoplegia  interior  \  asso- 
ciation of  both  conditions  is  called  ophthalmoplegia  totalis. 

2.  LOCATION  AND  CAUSES. 
The  optical  symptoms  of  an  eye-muscle  paralysis  can  be  produced 
by  cutting  one  of  the  six  muscles  concerned  in  the  eye's  move- 
ments.    This  has  often  enough  been  done,  as  a  "  myotomy  "  for 


LOCATION    AND    CAUSES.  435 

the  correction  of  squint.  At  the  present  day,  when  section  of  the 
tendon  has  displaced  section  of  the  muscle,  it  may  yet  occasionally 
happen  that  the  effect  of  a  tenotomy  is  too  strong,  and  produces  a 
paralysis  or  hemiparalysis  of  the  incised  muscle.  In  some  cases 
the  obliquus  inferior  is  loosened  by  an  accident  from  its  origin — the 
lateral  bony  edge  of  the  lacrimal  fossa — and  is  then  in  reality  par- 
alyzed. We  may,  however,  pass  over  such  cases  recognizable  by 
the  history  or  by  an  external  scar,  as  well  as  other  cases  due  to 
hemorrhages,  inflammations,  or  new  growths  in  the  orbit,  all  of 
which  may  lead  to  restriction  in  eye  movements.  There  still  remains 
the  majority  of  all  cases  of  squint  paralysis,  in  which  there  is  no 
demonstrable  lesion  or  disease  of  the  muscles  themselves ;  the 
cause  for  these  must,  therefore,  be  sought  for  in  the  nerves  of  the 
eye — the  oculomotorius,  the  abducens,  the  trochlearis — or  in  their 
tracts  in  the  brain. 

It  may  be  mentioned  here  that  an  isolated  lesion  of  the  individual  eye  muscles  is  by  no 
means  impossible.  Why  is  it  not  probable  that  the  same  process  is  at  work  in  the  orbit, 
which  here  and  there  aft'ects  individual  muscles  of  the  extremities  and  makes  them  pain- 
ful and  destroys  their  function  by  rheumatism  ?  Such  a  process,  considering  the  inac- 
cessibility of  the  eye  muscles,  would,  to  be  sure,  be  hard  to  diagnosticate  or  to  dififeren- 
tiate  from  disease  of  the  nerves. 

Assuming  that  a  disease  of  the  nerves  is  present,  an  exhaustive 
diagnosis  must  elucidate  a  three-fold  problem  : — 

(/)  The  spot  in  the  path  of  the  nerve  which  is  incapable  of  func- 
tionating. 

{2)  The  nature  of  the  disease, — whether  the  nerve  is  idio- 
pathically  affected,  whether  it  is  involved  in  disease  of  adjacent 
structures,  or  whether  it  is  merely  mechanically  implicated. 

(j)  The  ultimate  cause  of  the  disease,  whether  infection,  intoxi- 
cation, or  injury. 

Only  in  exceptional  cases  is  it  possible  to  demonstrate  these  three 
points  with  satisfaction.  The  first  offers  extraordinary  difficul- 
ties on  account  of  the  very  complicated  path  of  the  nerve  in  the 
brain,  and  since  many  questions  of  brain  anatomy  are  yet  unsettled, 
the  description  here  given  can  be  only  an  incomplete  one. 

(/)  The  most  important  aid  to  exact  localization  of  that  portion  of 
the  nerve  deprived  of  function  consists  in  establishing  the  presence 
of  other  nerve  paralyses  not  necessarily  limited  to  the  eye,  and  con- 
firmed by  a  careful  examination  made  by  the  neurologist.  As  it 
may  be  assumed  that  such  paralyses  arise  from  the  same  focus  in 


436  DISTURBANCES    IN   THE    MOVEMENTS    OF    THE    EYES. 

the  brain,  we  may  localize  the  disease  at  the  spot  where  the  paths 
of  the  paralyzed  muscles  are  close  together.  For  example,  if  paraly- 
sis of  the  left  abducens  occurs  with  paralysis  of  the  right  arm  and 
leg,  we  may  assume  a  focus  in  the  lower  left  portion  of  the  pons, 
since  in  this  spot  the  abducens  for  the  same  side  of  the  body,  and 
the  nerves  for  arm  and  leg  of  the  opposite  side,  lie  close  together. 

Localization  in  oculomotor  paralysis  is  particularly  difficult, 
since  this  nerve  in  its  entrance  into  the  orbit  divides  into  numerous 
branches  and  twigs,  and  since  it  arises  with  many  roots  from  its 
nucleus  on  the  floor  of  the  aqueduct  of  Silvius  {Fig.  iij,  p.  joj). 
There  is  little  difficulty  if  all  muscles  innervated  by  the  oculo- 
motor are  paralyzed  and  if  play  of  pupil,  accommodation,  most  eye 
movements,  and  elevation  of  lid  are  lacking.  In  such  a  case  we 
may  assume  a  disease  of  the  origin  of  the  nerve  at  the  base  of  the 
brain.  In  rare  cases  a  paralysis  of  all  oculomotor  branches  is  to 
be  referred  to  disease  of  the  nucleus  in  the  medulla,  but  such  a  con- 
dition can  be  diagnosticated  only  by  the  course  of  the  disease.  The 
paralysis  of  the  iris  and  ciliary  muscle  appears  earlier  or  later  than 
that  of  the  external  eye  muscles.  The  nuclei  for  the  pupil  and  for 
accommodation  {Fig.  iij,  p.  J05)  are  quite  independent  of  the 
others  in  spite  of  their  great  proximity.  According  to  Mauthner 
this  depends  upon  the  fact  that  these  nuclei  are  nourished  by  differ- 
ent terminal  arteries,  and  that  the  brain  area  nourished  by  each  ter- 
minal artery  is  of  itself  a  focus  for  an  independent  lesion.  If  accom- 
modation and  pupillary  action  are  unimpaired  we  are,  therefore, 
warranted  in  assuming  an  oculomotor  paralysis  to  be  a  nuclear 
paralysis.  Even  if  the  diseased  focus  increases  in  dimension  and  if 
paralysis  attacks  all  the  external  muscles  of  one  or  both  eyes,  those 
supplied  by  abducens  and  trochlearis  included,  the  retention  of 
pupillary  action  and  accommodation  warrants  the  diagnosis  of 
nuclear  paralysis,  because  in  the  nuclear  region  the  individual  ocu- 
lomotor nuclei  are  comparatively  wide  apart,  while  in  the  nerve 
itself  all  fibers  are  crowded  comparatively  close  together.  For  the 
same  reason  Mauthner  assumes  a  nuclear  paralysis  if  the  inner  eye 
muscles — sphincter  pupillse  and  ciliary  muscles — are  paralyzed,  or 
if  a  definite  movement,  convergence,  for  example,  is  impossible. 

If  a  single  muscle  supplied  by  the  oculomotor  is  paralyzed,  we  speak  at  once  of  nuclear 
paralysis.  It  is  a  question  whether  or  not  this  is  correct.  The  possibility  of  disease  of 
the  muscle  itself  has  been  already  mentioned.  By  neglecting  this,  there  are  still  other 
possibilities  which  must  be  thought  of,  especially  since  the  latest  investigations  have 


LOCATION  AND  CAUSES.  437 

shown  that  circumscribed  groups  of  ganglion  cells,  so-called  nuclei,  may  have  the  signi- 
ficance of  functionating  centers,  that  is,  they  may  control  certain  movements  through 
which  different  muscles  are  brought  into  play.  This  all  indicates  that  a  paralysis  of  con- 
vergence is  a  nuclear  paralysis.  But  isolated  paralyses  of  single  muscles,  say  of  the  in- 
ternal rectus,  may  be  otherwise  explained.  The  following  possibilities  may  be  thought 
of:— 

(rt)  The  nerve  might  be  diseased  close  to  the  entrance  into  the  muscle ; 

(d)  The  fibers  to  each  muscle  might  be  independently  diseased  in  the  nerve  trunk  ;  a 
condition  well  recognized  by  neurologists,  who  have  frequent  opportunity  of  observing 
that  a  toxic  neuritis,  such  as  lead  or  arsenic  paralysis,  attacks  special  fibers  of  a  nerve 
trunk ; 

(<■)  The  intracerebral  roots  of  the  nerve  fibers  and  the  ganglion  cells  belonging  to 
them,  though  perhaps  separated  in  space,  might  degenerate  independently.  Such  a  case, 
as  well  as  the  one  mentioned  under  i>,  might  be  designated  "systemic  disease"  in  the 
physiological  sense  of  the  word. 

Whatever  may  be  the  conclusion  about  such  possibilities,  I  am  sure  that  the  diagnosis 
— nuclear  paralysis — has  been  used  .altogether  too  freely.  Siemerling  has  recently  pub- 
lished a  case  of  ophthalmoplegia  externa,  in  which  anatomical  examination  showed  the 
oculomotor  nucleus  normal,  while  the  intracerebral  roots,  their  continuation  in  the  nerve 
trunk,  and  their  terminal  branches,  as  well  as  the  muscles  themselves,  were  all  found 
diseased. 

Uhlhoff 's  investigations  also  have  shown  that  it  is  sometimes  going  too  far  when  the 
conclusion  is  drawn  from  functional  disturbances  seen  during  life  that  there  must  be  defi- 
nite anatomical  changes.  Uhlhoff  has  found  at  the  autopsy  that  the  oculomotor  root  at 
the  base  of  the  brain  was  the  seat  of  the  lesion,  although  only  particular  muscles  of  those 
supplied  by  the  oculomotor  were  paralyzed  during  life  ;  and  in  other  cases  the  muscles 
supplied  by  the  oculomotor  functionated  normally  during  life,  although  at  the  autopsy  the 
oculomotor  trunk  was  found  diseased. 

The  brain  cortex  or  the  track  between  cortex  and  nuclear  region 
must  finally  be  mentioned  as  a  location  for  the  lesion.  If  a  diseased 
focus  lies  here,  the  condition  is  to  be  termed  a  "conjugate"  or 
"  associated "  disturbance  of  movement,  and  not  an  eye-muscle 
paralysis  in  a  restricted  sense.  This  disturbance  of  movement  con- 
sists of  inability  on  the  patient's  part  to  carry  out  those  associated 
visual  movements  which  respond  to  light  stimulation,  while  the 
same  visual  movements  may  be  properly  performed  either  volun- 
tarily, or  through  aural  or  tactile  stimulation.  As  a  rule,  this  con- 
jugate disturbance  of  eye  movement  shows  itself  as  a  conjugate 
deviation.  An  exception  from  this  is  the  "  cerebral  ptosis,"  that  is, 
an  isolated  paralysis  of  one  levator  palpebrae  superioris,  the  cause 
of  which  may  be  found  at  the  autopsy  to  be  a  lesion  in  the  anterior 
portion  of  the  cortex  of  the  opposite  side. 

{2)  As  far  as  concerns  the  nature  of  the  disease  we  may  distin- 
guish : — 

[a)  Independent  affections  in  the  course  of  the  nerve,  as  neuritis, 


438  DISTURBANCES    IN    THE    MOVEMENTS    OF    THE    EYES. 

perineuritis,  inflammation  of  the  nuclei  (polioencephalitis,  inflam- 
mation of  the  gray  matter  in  the  ganglia  on  the  floor  of  the  fourth 
ventricle  and  aqueduct  of  Silvius),  with  destruction  of  the  ganglion 
cells,  scleroses,  and  degeneration  of  individual  groups  of  ganglion 
cells, 

{b)  Diseases  of  neighboring  tissues  which  involve  the  nerves  or 
their  roots,  as  inflammations,  new  growths,  softening,  and  degen- 
eration foci. 

{c)  Diseases  of  remote  tissues  which,  in  a  mechanical  way,  inter- 
rupt or  hinder  conduction  along  the  nerves,  as  new  growths  and 
hemorrhages. 

Which  of  these  causes  is  at  work  can  be  found  out  only  by  study- 
ing the  history  and  the  general  condition  of  each  case.  Often 
enough  this  does  not  suffice.  Not  infrequently  paralysis  of  a  lid 
or  eye  muscle  may  be  the  first  and  but  fleeting  sign  of  a  grave  brain 
or  spinal  cord  lesion,  such  as  tabes  dorsalis,  multiple  sclerosis,  or 
progressive  paralysis.  Tubercular  meningitis  and  tumors  of  all 
kinds  may  produce  an  eye-muscle  paralysis. 

(j)  As  essential  causes  of  the  brain  lesions  here  enumerated, 
various  infections  must  bear  the  blame.  Syphilis  especially  must 
be  charged  with  causing  ten  to  20  per  cent.,  or  according  to  v.  Graefe 
50  per  cent,  of  all  cases.  Equally  as  common  are  the  paralyses 
from  tuberculosis  of  the  meninges,  other  forms  of  meningitis  being 
less  disastrous.  Another  group  of  paralyses,  those  caused  by  the 
poison  of  diphtheria,  is  of  great  interest  to  the  ophthalmologist. 
Usually  the  muscle  of  accommodation,  less  so  an  external  eye 
muscle,  is  affected.  Finally,  Grippe,  rheumatism,  typhoid  and 
other  poisons  like  nicotin,  alcohol,  lead,  ptomains,  carbonic  oxide 
gas,  have  all  been  causes.  Occasionally  an  eye-muscle  paralysis 
has  been  traced  to  a  cerebral  hemorrhage  due  to  arterial  sclerosis, 
diabetes,  or  fractures  at  the  base  of  the  brain. 

3.  PROGNOSIS. 
This  is  favorable  in  paralyses  that  result  as  a  sequel  to  diph- 
theria or  from  some  mild  injury  or  transient  intoxication.  It  is 
doubtful  in  paralyses  from  some  unknown  cause,  or  from  what  for 
tradition's  sake  we  love  to  call  "  catching  cold."  Such  "colds" 
may  return  after  a  time,  bringing  associated  paralyses  of  other 
nerves  with  them,  and  then  the  true  nature  of  the  disease  may  be 
made  out.     The  prognosis  is  bad  in  paralyses  which  are  recognized 


TREATMENT.  439 

with  the  presence  of  other  pathological  signs  as  but  a  part  of  some 
grave  spinal  cord  or  brain  lesion. 

4.  TREATMENT. 

This  should  begin  by  covering  the  unsound  eye  to  prevent  the 
double  vision  and  the  accompanying  vertigo,  after  which  the  cause 
of  the  trouble  must  be  attacked,  supposing  that  it  can  be  discov- 
ered. If  there  is  syphilis,  mercury,  diaphoresis  by  medicine  or 
bath,  and  large  doses  of  iodid  of  potassium  are  to  be  used.  Dia- 
betes demands  the  proper  diet  and  hygiene.  Injuries  must  be 
treated  by  rest.  Diphtheritic  paralysis  usually  heals  by  proper 
bodily  nutrition,  as  do  also  cases  due  to  mild  intoxication ;  a  deep- 
seated  lead  palsy,  on  the  contrary,  heals  neither  of  itself  nor  by 
treatment.  In  all  cases  due  to  some  obscure  cause,  a  specific  treat- 
ment is  impossible,  but  we  need  not,  therefore,  condemn  the  numer- 
ous remedies  so  warmly  recommended  for  "paralysis."  Bleeding, 
cathartics,  diaphoresis,  large  doses  of  iodid  of  potassium,  exercise  to 
the  (half)  paralyzed  muscle,  and  electricity — either  the  galvanic  or 
faradic  current — are  at  our  disposal.  A  trial  of  iodid  of  potassium 
is  always  to  be  recommended,  even  if  the  patient  confesses  no  syph- 
ilitic infection  and  if  no  signs  of  it  are  present. 

If  the  paralysis  continues  in  spite  of  these  methods  and  there  is 
no  likelihood  of  cure,  there  remains  the  task  of  relieving  the  patient 
from  the  severest  and  most  distressing  disturbance,  the  double 
vision.  In  some  cases  this  is  not  present,  for,  besides  the  eye 
muscles  themselves,  the  levater  may  be  paralyzed  and  the  droop- 
ing lid  will,  therefore,  exclude  the  unsound  eye  from  its  part  in 
vision  ;  or  tabes  may  have  progressed  so  far  that  the  diplopia  is  no 
longer  perceived  because  the  optic  nerve  is  attacked  and  visual 
acuity  thus  reduced  in  addition  to  the  oculomotor  paralysis. 

If  double  images  are  present  to  the  patient's  discomfort  an 
attempt  can  be  made  to  fuse  them  by  means  of  prisms.  In  spite  of 
the  theoretical  objection  that  a  special  prism  is  needed  for  each 
visual  direction  or  none  at  all  needed  when  the  eye  looks  toward 
the  healthy  side,  prisms  have  shown  themselves  serviceable  in  many 
cases.  Such  cases  have  a  decided  range  of  fusion.  Suppose  the 
left  external  rectus  to  be  paralyzed  and  an  extensive  range  of  fusion 
present,  a  prism  of  ^°,  6° ,  or  8° ,  base  outward,  may  produce  single 
vision  for  a  part  of  the  visual  field  lying  to  the  left,  while  in 
looking  straight  ahead  or  toward  the  right  fusion  may  be  main- 


440  DISTURBANCES    IN   THE   MOVEMENTS    OF   THE    EYES. 

tained  by  contraction  of  the  two  interni,  that  is,  by  intentional  con- 
vergence. 

In  other  but  less  common  cases  the  harmony  of  eye  movements 
may  be  restored  by  weakening  (tenotomy)  the  power  of  an  associa- 
ted muscle  of  the  sound  eye ;  much  more  importance  is,  however, 
attached  to  the  use  of  the  eyes  than  to  their  excursion.  Suppose  a 
left  superior  oblique  to  be  half  paralyzed  ;  ought  an  oblique  muscle 
or  the  inferior  rectus  of  the  right  eye  to  be  tenotomized  ?  Obvi- 
ously the  latter,  for  since  both  oblique  muscles  have  an  abducting 
factor,  it  would  only  increase  the  tendency  to  convergence  and 
homonymous  double  images  if  a  remaining,  unaffected  oblique 
muscle  were  weakened ;  while  to  weaken  the  right  inferior  rectus, 
which  is  an  adductor,  would  decrease  the  moderate  tendency  to 
convergence  and  still  more  decrease  the  difference  in  elevation  of 
the  double  images,  than  would  a  tenotomy  of  a  right  oblique  mus- 
cle— an  operation,  it  may  be  remarked,  very  difficult  to  perform. 
In  studying  this  rotatory  factor  we  learn  that  the  superior  oblique 
of  one  eye  is  associated  in  movement  with  the  inferior  rectus  of  the 
other. 

In  the  majority  of  cases  of  lasting  eye-muscle  paralysis  nothing 
can  be  done  beyond  excluding  the  paralyzed  eye  from  vision  by  a 
bandage  or  an  opaque  glass  in  the  spectacle  frame.  If  secondary 
contracture  develops  during  the  disease  the  treatment  is  to  be  that  of 
concomitant  squint  given  on  p.  ^^5  ;  but  an  attempt  should  be  made 
to  oppose  the  development  of  this  contracture  by  Michel's  method, 
which  consists  in  stretching  the  antagonist  of  the  paralyzed  muscle. 
This  is  done  by  seizing  a  fold  of  the  conjunctiva  in  fixation  forceps 
and  then  repeatedly  rotating  the  eye  toward  the  side  of  the  paralyzed 
muscle. 


II.  STRABISMUS  CONCOMITANS,  Concomitant  Squint,  with 
Particular  Reference  to  Convergent  Squint. 

1.  VISION  IN  STRABISMUS. 
Convergent  squint  develops  nearly  always  in  early  childhood.  In 
the  beginning  it  shows  itself  only  at  intervals  as  strabismus  periodi- 
cus,  and,  as  attentive  mothers  may  observe,  usually  when  the  child 
is  looking  at  a  near  object.  The  squinting  position  becomes  more 
frequent  until  it  has  finally,  even  if  after  years,  become  constant. 


VISION    IN    STRABISMUS.  44 1 

In  case  the  same  eye  always  deviates,  the  condition  is  called  strab- 
ismus wiilateralis  ;  if  both  eyes  are  alternately  used  for  fixation,  first 
one  and  then  the  other  deviating,  the  condition  is  called  strabismus 
alterna?is.  The  demonstration  and  the  measurement  of  the  eye's 
deviation  has  already  been  given  on  p.  8g.  With  reference  to  the 
diagnosis  only  the  differences  between  paralytic  squint  and  concomi- 
tant squint  need  be  here  emphasized. 

In  paralytic  squint  there  is  : —  In  concomitant  squint  there  is  : — 

(1)  Contraction  of  the  Field  of  Vis-  (l)  Displacement  of  the  Field  of  Vis- 
ion ;  ion,  but  no  contraction  ; 

(2)  Secondary  deviation  greater  than  (2)  Secondary  deviation  equal  to  the 
the  primary  ;  primary  ; 

(3)  Disturbance  with  double  images.  (3)  No  disturbance  with  double 

images. 

The  first  point  needs  nothing  more  than  what  is  said  on  /.  8g. 
The  second  needs  a  short,  but  the  third  an  elaborate  explanation. 

(2)  In  concomitant  squint  the  position  of  the  eyes  in  relation  to 
each  other  is  faulty,  but  the  movements  of  the  eyes  are  quite  nor- 
mal. For  example,  suppose  there  is  convergent  squint  with  the  left 
eye  squinting.  If  the  right  (the  fixing)  eye  is  turned  to  the  right, 
an  .equally  strong  impulse,  according  to  the  rule  of  association 
between  eye  muscles,  is  sent  to  the  internal  rectus  of  the  left  eye, 
and  the  result  is  that  both  eyes  are  turned  toward  the  right  with 
unchanged  degree  of  convergence.  If  the  right  eye  is  now  cov- 
ered and  the  left  induced  to  fix,  the  latter  must  pass  out  of  its 
position  of  squint  by  an  impulse  sent  to  its  external  rectus.  This 
is  not  possible  without  sending  an  equally  strong  impulse  to  the 
internal  rectus  of  the  right  eye,  in  consequence  of  which  the  right 
eye  also  turns  to  the  left  an  equal  amount,  that  is,  an  amount  equal 
to  the  angle  of  squint.  This  "  secondary  deviation  "  of  the  right  eye 
is,  therefore,  just  as  great  as  the  **  primary  deviation  "  of  the  left  eye. 

(3)  Having  confirmed  what  has  been  said  (/.  yo)  about  projec- 
tion of  retinal  images  and  {p.  428)  the  conditions  in  muscle  paraly- 
sis, we  might  suppose  that  in  concomitant  squint  there  would  also 
be  double  images — homonymous  in  convergent,  heteronymous  in 
divergent  squint.  Experience  shows  that  this  is  not  so,  but  that 
the  patient  does  not  see  at  all  with  the  squinting  eye  the  object 
fixed  by  the  normal  eye,  or,  in  other  words,  that  the  retinal  image 
of  the  squinting  eye  remains  unperceived.  This  does  not  mean 
that  the  squinting  eye  is  entirely  excluded  from  participation  in  the 


442  DISTURBANCES    IN    THE    MOVEMENTS    OF   THE    EYES. 

visual  act.  It  can  be  easily  demonstrated  that  objects  within  the 
visual  field  of  the  squinting  eye  are  partly  seen,  partly  not  seen, — 
that  there  is  a  "  regional  exclusion."  At  all  events,  the  squinting 
eye  perceives  everything  lying  within  that  part  of  the  total  visual 
field  belonging  to  the  squinting  eye  alone.  Since  in  divergent 
squint  the  individual  fields  coincide  in  a  smaller  area  than  normal, 
the  total  visual  field  must,  therefore,  be  greater;  in  convergent 
squint,  for  a  corresponding  reason,  it  must  be  smaller  than  normal. 
Objects  lying  within  that  part  of  the  visual  field  common  to  both 
eyes  are  not  all  necessarily  excluded  from  the  squinting  eye,  but 
only  those  that  would  disturb  the  vision  of  the  healthy  eye.  For 
example,  many  squinting  patients  say  that  when  reading  they  see 
double  at  the  beginning  or  end  of  a  line,  that  is,  that  the  image  in 
the  squinting  eye  is  not  suppressed  if  it  appears  on  the  background 
of  white  paper,  but  that  it  is  suppressed  when  it  appears  at  a  spot 
where  letters  are  seen  by  the  healthy  eye.  Reading  would,  of 
course,  be  quite  impossible  if  each  eye  projected  different  letters  to 
the  same  spot  in  space ;  diplopia  for  objects  seen  at  one  side 
causes,  however,  little  disturbance,  a  condition  explainable  by 
what  has  been  said  about  the  presence  of  physiological  double 
images  (/.  /j).  It  is  easy  to  understand,  too,  that  the  fixing  eye 
will  conquer  when  there  is  a  struggle  between  images  of  different 
objects  for  the  same  spot  in  space.  The  normal  eye,  on  the  one 
hand,  has  a  better  visual  acuity  (/.  4^4),  and,  on  the  other  hand,  it 
uses  in  the  struggle  its  most  sensitive  retinal  area,  while  the  squint- 
ing eye  must  be  content  with  eccentric  vision  from  a  more  peri- 
pheral and  less  sensitive  retinal  area. 

This  suppression  of  retinal  images  on  certain  areas  is  the  means  adopted  by  the  eye 
for  freeing  itself  from  the  disturbance  of  diplopia.  The  process  is  a  psychical,  although 
an  unconscious  one,  accomplished  by  association  of  action  in  the  two  eyes.  This,  and 
other  conditions  also,  may  be  established  from  the  fact  that  the  double  images  unnoticed 
by  the  patient  are,  in  most  cases,  made  perceptible  by  simple  means.  Many  who  squint 
see  double  as  soon  as  their  attention  is  called  to  it.  Others  may  be  made  to  see  double 
by  placing  a  dark-colored  glass  in  front  of  the  eye  with  the  better  vision.  If  this  does 
not  suffice,  a  prism,  with  base  down  or  up,  should  be  placed  in  front  of  the  deviating  eye, 
while  the  dark-colored  glass  remains  in  front  of  the  fixing  eye.  In  the  deviating  eye 
there  will  then  be  formed  an  image  of  the  object  fixed  by  the  healthy  eye,  this  image  fall- 
ing upon  a  retinal  area  where  retinal  images  have  not  as  yet  been  suppressed  because 
they  arose  from  objects  seen  peripherally  by  the  healthy  eye  also.  We  have  now  a  con- 
dition which  the  squinting  eye  has  not  learned  to  treat  to  its  best  advantage.  In  some 
cases  double  images  cannot  be  produced  by  any  artifice  whatever. 

The  preceding  statement  in  no  way  contradicts  the  laws  of  projection  already  given 


CAUSES.  443 

(/.  70),  but  only  shows  that  nature  can  evade  such  laws  in  the  interest  of  single  vision. 
There  are,  however,  some  squinting  persons  in  whom  retinal  images  are  really  projected 
otherwise  than  ought  to  be  expected  from  the  law  of  projection.  Many  such  patients, 
after  double  vision  has  been  produced  by  the  use  of  a  co  ored  glass,  assert  that  there  is 
such  a  distance  between  the  two  images  as  would  show  a  direct  contradiction  to  the  actual 
position  of  squint,  since  this  distance  must  be  too  small  for  the  demonstrable  angle  of 
squint.  There  are  even  cases  with  binocular  fusion  in  spite  of  a  squint,  that  is,  cases  in 
which  the  retinal  image  on  the  fovea  centralis  of  the  fixing  eye  is  fused  with  the  image 
formed  on  a  peripheral  (unequal  and  weaker)  retinal  area  of  the  other  eye.  It  is  seen, 
therefore,  that  the  law  of  "  identical  retinal  areas"  is  anatomically  favored  by  equal 
visual  acuity  of  identical  areas  and  is  perpetuated  by  use  of  such  eyes,  but  that  this  law 
can  be  violated  by  a  continued  position  of  squint.  Such  violation  is  unnatural.  This 
may  be  seen  in  the  results  of  overcoming  convergence  by  an  operation  ;  at  first  crossed 
double  images  appear,  as  if  divergence  were  present  instead  of  the  normal  position,  but 
this  condition  does  not  last  long  ;  after  a  few  days  the  natural  association  of  retinal  images 
masters  the  acquired  association  and  the  double  images  disappear. 

2.  CAUSES. 

The  eyes  when  closed  are  in  a  position  of  equiHbrium.  The 
form  and  direction  of  the  orbits,  the  length,  thickness,  and  attach- 
ment of  the  eye  muscles,  the  shape  of  the  eyeball,  in  short,  the 
anatomical  relations  of  the  eye,  its  soft  and  its  bony  surroundings, 
all  have  their  influence  on  this  position  of  equilibrium.  As  a  rule, 
though  not  always,  these  anatomical  relations  are  the  same  for  both 
eyes.  On  account  of  the  distinctly  appreciable  divergence  of  the 
orbits  this  position  of  equilibrium  might  also  be  divergent,  but 
as  divergence  of  the  visual  axes  is  not  used  in  vision,  the  position  is 
rather  that  of  parallelism,  or  even  of  convergence  for  near  work. 
Since  the  use  to  which  an  organ  is  put  has  a  decided  influence  on 
its  anatomical  structure,  it  is  probable  that  the  eye  muscles  develop 
during  early  childhood  so  as  to  make  parallelism  of  the  visual  axes 
the  position  of  equilibrium.  Parallelism  of  that  exactness  requisite 
for  distant  vision  is,  however,  confirmed  by  anatomical  relations 
only  in  the  rarest  cases. 

From  the  above  it  may  be  deduced  that  squint  depends  upon  a 
deviation  of  one  or  both  eyes  from  the  fionnal  position  of  equilibrinm. 

We  must,  then,  find  out  whether  the  disturbance  of  equilibrium 
is  produced  by  anatomical  conditions  alone,  or  by  physiological 
conditions  as  well,  perhaps  by  an  habitually  over-strong  nervous 
impulse  to  the  internal  muscles. 

It  must  be  remembered  that  the  need  of  proper  adjustment 
of  the  eyes  exists  only  for  the  sake  of  binocular  single  vision.  If 
this  need  is  lacking,  or  if  the  eye  is  influenced  by  unequal  visual 


444  DISTURBANCES    IN    THE    MOVEMENTS    OF   THE    EYES. 

acuity  ^  or  unequal  refractive  condition,  it  is  evident  that  the  least 
disturbance  of  muscular  equilibrium  must  lead  to  squint.  Con- 
versely, if  visual  acuity  and  refractive  conditions  are  equal,  and  if 
the  will  power  is  strong  enough,  a  considerable  disturbance  of 
muscular  equilibrium  may  be  present  without  causing  squint, 
because  the  impulse  or,  in  certain  cases,  the  desire  for  binocular 
simple  vision  can,  in  a  physiological  manner,  take  the  place  of  a 
muscular  equilibrium  not  supplied  anatomically.  In  this  sense  we 
may  speak  of  inequality  in  visual  acuity  as  direct  cause  of  squint. 

It  must  be  further  remembered  that  a  second  influencing  factor 
lies  in  the  association  of  convergence  and  accommodation  (/.  yg). 
The  proper  position  of  the  eyes  can  be  thereby  induced,  even  if,  on 
account  of  weaksightedness,  there  is  no  need  for  it.  But  this  very 
factor  becomes  a  cause  of  squint  if  refractive  error  is  present. 
Hyperopia  calls  out  an  abnormally  strong  accommodation  with  its 
consequent  convergence,  which  is  greater  than  is  necessary  for  the 
distance  of  the  object  fixed.  Conversely,  in  myopia  the  accommo- 
dation is  not  so  great  as  normal  and  the  convergence  is  insuffi- 
cient, so  that  a  divergent  position  is  assumed  in  fixing  a  near  objeet. 
Although  convergent  squint  in  hyperopia,  or  divergent  squint  in 
myopia,  is  often  enough  prevented  by  the  impulse  for  binocular 
fusion  (or  by  the  favorable  anatomical  conditions  in  the  first  case), 
there  are,  nevertheless,  numerous  examples  of  squint  caused  by 
refractive  errors,  the  more  naturally,  of  course,  the  less  interest 
there  is  for  binocular  fusion.  The  question  as  to  the  cause  of  the 
squint  is,  therefore,  in  such  cases — and  they  are  the  majority — 
completely  answered. 

There  yet  remains  a  minority  of  cases  where  refractive  errors  are 
not  present,  or  where  the  form  of  squint  does  not  correspond  to 
them, — cases,  for  example,  where  hyperopia  is  associated  with  di- 
vergent, myopia  with  convergent  squint.  Rare  cases  of  upward  or 
downward  squint  are  not  of  themselves  necessarily  due  to  refrac- 
tive errors.     For  all  such  cases  we  assume  that  they  depend  either 


^  Reduced  visual  acuity  in  the  squinting  eye  is  so  common  as  to  be  the  rule.  It  de- 
pends either  upon  corneal  opacities,  lens  opacities,  astigmatism,  or — in  most  cases — has 
no  discoverable  cause.  Such  an  amblyopia  is  either  the  cause  or  the  effect  of  the  squint, 
or  it  may  be  both.  Congenital  amblyopia  of  one  eye  may  as  naturally  induce  squint  as 
acquired  amblyopia.  Cases  have  been  reported  in  which  the  deviating  eye  was  at  first 
normal,  but  became  weak  after  some  years.  This  is,  of  course,  amblyopia  ex  anopsia 
(/•  383)- 


TREATMENT.  445 

upon  improper  innervation,  as  convergent  squint  due  to  an  habitu- 
ally stronger  innervation  of  one  or  both  interni ;  or  upon  anatomical 
conditions,  as  a  greater  diameter  of  the  internal  or  external  rectus, 
and,  perhaps,  an  insertion  of  the  muscle  closer  to  the  cornea;  or, 
finally,  upon  a  restoration  of  normal  physiological  or  anatomical 
relations. 

The  circumstance  that  many  a  squint  disappears  in  sleep,  during  narcosis,  or  after  death 
gives  support  to  the  assumption  that  concomitant  squint  may  be  caused  by  improper  inner- 
vation of  one  or  both  interni.  And  since  cases  have  been  reported  where  the  squint 
continued  partially  or  entirely  after  death,  we  may  likewise  derive  support  for  the  assump- 
tion that  such  cases  were  due  to  anatomical  causes. 

Further  examples  of  squint  through  nervous  influences  are  found  in  those  cases  that 
begin  reflexly  as  the  result  of  conjunctival  or  corneal  irritation.  Moreover,  cases  of 
concomitant  squint  developing  from  paralytic  squint  (/.  4Jj)  are  to  be  indirectly  at- 
tributed to  a  nervous  influence,  since  a  muscle  released  from  the  counterbalance  of  its 
(paralyzed)  antagonist  takes  a  condition  of  indirect  contraction. 


3.  TREATMENT. 

Treatment  must  always,  if  possible,  attack  the  cause.  If  the 
visual  acuity  of  the  deviating  eye  is  weak,  an  attempt  must  be  made 
to  improve  it.  At  times  this  can  be  done  by  neutralizing  an  astig- 
matism or  by  an  iridectomy,  or  in  amblyopia  without  cause  by 
exercising  that  eye.  Exercise  of  a  weak  eye  is  most  easily  accom- 
plished by  occasionally  bandaging  the  other,  but  success  may  be 
expected  only  when  this  exercise  is  begun  in  early  childhood. 

In  case  a  refractive  error  is  the  cause  of  squint,  we  have  a  remedy 
for  it  in  neutralizing  glasses,  and  we  actually  see  many  a  manifest, 
convergent  squint  disappear  after  a  few  months'  use  of  neutralizing 
lenses.  If  this  result  is  not  attained  the  treatment  must  be  opera- 
tive. Nevertheless,  it  must  always  be  remembered  that  the  con- 
vergent squint  of  children  quite  often  heals  of  itself,  either  because 
the  hyperopia  becomes  emmetropia  or  irrespective  of  it.  The 
operation  should,  therefore,  not  be  done  before  the  seventh  year, 
and  only  then  if  squint  has  existed  some  years  and  has  defied  treat- 
ment with  glasses.  In  divergent  squint  a  spontaneous  cure  does 
not  take  place. 

The  operations  are  : — 

(i)  Tenotomy  of  the  muscle  acting  too  powerfully; 

(2)  Advancement  of  the  muscle  acting  too  weakly ; 

(3)  A  combination  of  the  two. 

In  convergent  strabismus  of  slight  to  moderate  degree — j  to  7 


446 


DISTURBANCES    IN    THE    MOVEMENTS    OF    THE    EYES. 


^ 


mm. — tenotomy  of  one  or  both  interni  may  not  only  restore  the 
correct  position,  but  effect  the  normal  mobility  of  the  eyes.  If  the 
tendon  of  a  rectus  muscle  is  cut  close  to  its  insertion  in  the  sclera 
it  retracts  only  j.j  to  5  mm.  and  heals  there  ;  farther  retraction  is 
prevented  by  its  peripheral  attachments,  that  is,  by  the  connective- 
tissue  fibers  that  pass  from  the  side  of  the  muscle  or  tendon  sheath 
to  the  eyeball  and  establish  a  loose  connection  with  it.  Obviously 
the  adduction  of  the  eye  decreases  by  about  the  amount  to  which 
the  tendon  is  set  back.  This  does  not  signify  the  actual  loss,  since 
the  adductive  power  was  above  normal,  and  the  loss  of  adduction 
will,  to  a  great  extent,  appear  again  in  the  gain 
of  abduction.  If  the  retraction  of  one  internal 
rectus  does  not  suffice,  of  course  we  may  resort 
to  the  same  operation  on  the  healthy  eye,  for  the 
association  of  the  two  muscles  in  the  horizontal 
meridian  has  the  effect  of  giving  to  the  operation 
on  the  healthy  eye  the  same  result  in  the  mutual 
position  of  the  two  as  the  same  operation  has  on 
the  deviating  eye. 

In  very  pronounced  squint  even  a  double  tenot- 
omy will  not  suffice  to  reproduce  the  normal 
position.     Under  such  circumstances  the  rectus 
internus  must  be  severed  and  allowed  to  retract, 
and  the  rectus  externus  must  be  advanced,  that 
is,  sutured  by  its  tendon  closer  to  the  cornea 
than  the  original  insertion.     It  is  advisable  to 
perform  the  advancement  of  the  externus  about 
a  week  after  the  tenotomy  of  the  internus,  so  that 
the  latter  will  then  have  firmly  healed  ;  the  simultaneous  perform- 
ance of  both  operations  allows  too  much  retraction  of  the  tendon 
of  the  internus,  and  the  loss  of  adduction  is  too  great. 

Tenotomy  of  Rectus  Internus. — Instruments  {p.  j^7) :  lid  speculum,  fixation  for- 
ceps, dissection  forceps  without  lock,  blunt  scissors  curved  on  the  flat,  the  so-called 
Louis'  scissors,  a  large  (a)  and  a  small  [b,  Fig.  /jj)  strabismus  hook,  needles  and  thread, 
cocain.      Disinfection  of  physician,  assistants,  all  instruments,  and  the  field  of  operation. 

The  patient  looks  straight  ahead,  and  an  assistant,  with  the  fixation  forceps,  seizes  a 
fold  of  conjunctiva  near  the  external  corneal  margin  and  rolls  the  eye  gently  outward. 
The  surgeon,  with  the  other  forceps,  seizes  a  parallel  fold  of  conjunctiva  in  front  on  the 
insertion  of  the  tendon  ^   of  the  internus  and  cuts  perpendicularly  upon  it.     Then  with 

^  The  line  of  insertion  of  the  internus  is  10.3  vim.  long  and  j-.j  vim.  from  the  cor- 
neal margin ;   of  the  externus  it  is  g.2  mm.  long  and  b.g  mm.  from  the  corneal  margin 

{Pig-  151)- 


Fig.  155. 

(a)  Large, 

(b)  Small  strabismus 
hook. 


ADVANCEMENT.  447 

short  strokes  of  the  scissors  beneath  the  conjunctiva  he  undermines  it  in  the  direction  of  the 
nose.  He  thus  uncovers  the  anterior  end  of  the  internus  tendon.  Next  he  passes  the 
larger  strabismus  hook,  held  flat  against  the  eye,  beneath  the  tendon,  draws  it  up  slightly, 
and  with  the  scissors  severs  it  from  the  sclera.  He  now  takes  the  small  strabismus  hook 
and  carries  it  close  behind  the  insertion  of  the  tendon  into  the  upper  and  lower  corner  of 
the  wound,  in  order  to  find  any  remaining  fibers  that  ought  to  be  severed. 

After  the  operation  is  finished  the  result  is  tested  by  comparing 
the  loss  of  adduction  (/.  go)  with  the  predominance  of  adduction 
that  was  present  before.  If  the  loss  of  adduction  is  greater  than 
was  intended,  the  result  may  be  reduced  by  taking  a  broad  hori- 
zontal conjunctival  suture.  Since  tendon  and  muscle  are  still  con- 
nected with  the  conjunctiva  farther  back,  such  a  conjunctival  suture 
will  draw  forward  the  muscle  which  is  too  much  retracted.  If  the 
result  is  insufficient,  a  second  operation  maybe  performed  six  weeks 
later. 

A  conjunctival  suture  may  be  needed  if  the  sclera  has  been  de- 
nuded. In  case  the  suture  is  taken  for  such  a  purpose,  the  result 
of  the  operation  will  not  be  affected  if  the  edges  of  the  wound  are 
seized  very  gently  or  if  the  suture  is  carried  perpendicularly. 

Advancement. — A  severed  tendon  may  be  advanced  by  a  broad 
and  tightly  drawn  suture  through  the  conjunctiva,  and  the  new  in- 
sertion of  the  tendon  will  lie  nearer  the  corneal  margin  than  the 
original  insertion.  Tenotomy  can,  therefore,  be  changed  to  an  ad- 
vancement by  a  proper  conjunctival  suture.  As  a  rule,  however, 
such  a  suture  is  not  relied  upon,  but  the  tendon  itself  is  sutured, 
close  to  the  corneal  margin,  either  to  the  conjunctiva  remaining  or 
to  the  sclera,  through  the  upper  layers  of  which  the  threads  pass. 

Recently  many  surgeons  have  preferred  to  advance  "  Tenon's  capsule  "  instead  of  the 
muscle  itself.  This  name  is  used  to  describe  a  connective-tissue  sheath,  in  which  the  eye 
rests  like  the  end  of  a  bone  in  its  capsule  at  a  joint.  This  sheath  is  connected  with  the 
eyeball  by  loose  and  elastic  connective-tissue  strands  ;  but  near  the  cornea  on  the  one  hand, 
and  near  the  entrance  of  the  ciliary  arteries  and  nerves  at  the  posterior  pole  on  the  other 
hand,  this  connection  becomes  more  intimate.  The  external  surface  of  Tenon's  capsule, 
that  is,  the  surface  from  the  eyeball,  is  continued  into  the  connective-tissue  envelope  of 
the  orbital  fat.  The  eye  muscles,  therefore,  are  outside  of  the  capsule,  and  their  tendons 
must  pierce  it  in  order  to  reach  the  eyeball.  They  do  not,  however,  pass  through  a 
smooth  aperture,  but  are  embraced  posteriorly  by  a  fold  of  this  capsule,  hence  the  ex- 
pression, "  peripheral  attachments"  (/.  446).  To  advance  Tenon's  capsule,  Wecker 
excises  a  semilunar  flap  from  the  conjunctiva,  in  front  of  the  insertion  of  the  too  weak 
muscle,  5  Tiim.  broad  and  10  vim.  high.  Then  he  cuts  into  Tenon's  capsule,  releases 
the  muscle  from  its  surrounding  attachments  without  separating  tendon  from  sclera,  and 
advances  Tenon's  capsule  to  the  corneal  margin  by  means  of  two  sutures  that  close  the 
conjunctival  wound  at  the  same  time. 


448  DISTURBANCES    IN    THE    MOVEMENTS    OF   THE    EYES. 

4.  AFTER-TREATMENT  AND  RESULTS. 

The  operation  for  squint  endeavors  to  reaccomplish  normal, 
binocular  single  vision,  that  is,  the  fusion  into  one  visual  percep- 
tion of  the  two  retinal  images  formed  of  one  external  object.  It 
can  be  tested  by  the  stereoscope  whether  this  fusion  takes  place, 
by  showing  parts  of  a  figure  to  the  right  eye  alone  and  other  parts 
of  the  same  figure  to  the  left  eye  alone ;  for  example,  a  horizontal 
line  to  the  right  eye  and  a  perpendicular  line  to  the  left  eye ;  if 
binocular  fusion  is  accomplished  the  figure  will  appear  as  a  cross. 
This  result  is,  however,  not  always  obtained.  The  position  of  the 
two  eyes  can,  in  the  best  cases,  be  made  about  right  by  one  or  more 
operations,  but  complete  restoration  of  function  depends  upon  the 
energy  of  the  two  eyes  to  respond  to  the  impulse  for  binocular 
fusion.  If  the  visual  acuity  of  the  eyes  is  unequal — as  it  is  in  most 
cases  of  squint — the  prompting  to  such  an  effort  is  lacking  and  the 
result  of  the  operation  must  be  restricted  to  its  cosmetic  effect, 
beautifying  the  patient.     That  is  usually  about  all  she  asks  for. 

For  complete  assurance  of  the  success  of  the  operation  we  must 
use  methods  by  which  a  desire  for  binocular  fusion  maybe  aroused 
or  encouraged.  The  best  visual  acuity  possible  must  be  obtained 
by  spherical  or  cylindrical  lenses,  and  exercise  in  fusion  of  retinal 
images  must  be  supplied  by  a  stereoscope.  Supplementary  aid  may 
be  given  by  favoring  convergence  if  the  position  of  the  eyes  is 
slightly  divergent,  or  by  favoring  divergence  if  the  eyes  are  slightly 
convergent.  Convergence  is  encouraged  by  looking  at  near  objects, 
by  stimulating  the  accommodation  with  concave  lenses,  and  by 
lowering  the  visual  plane.  Divergence  is  encouraged  by  resting 
the  eyes,  by  relaxing  accommodation  with  convex  lenses,  and  by 
elevating  the  visual  plane.  Lasting  success  for  an  operation,  no 
matter  how  successful  it  seemed  at  first,  can  be  expected  only  when 
binocular  fusion  is  completely  reproduced.  If  binocular  fusion  is 
faulty  it  often  happens  that  the  squint  returns  after  a  year  or  more 
— the  danger  being  that  divergent  squint  will  relapse  into  its  orig- 
inal condition  and  that  a  convergent  squint  will  relapse  into  the 
opposite  condition  and  become  divergent.  It  is  best,  therefore,  in 
operating  for  convergent  squint  to  do  too  little  rather  than  too 
much,  especially  since  a  trifling  convergence,  say  of  /  mvi.,  is  not 
displeasing,  or  certainly  less  displeasing  than  an  equal  amount  of 
divergence.  To  complete  and  to  retain  the  result  of  an  operation, 
if  binocular  vision  has  always  been  lacking,  one  must  often  be 


LATENT    STRABISMUS.  449 

content  to  encourage  or  to  overcome  convergence  by  any  of  the 
methods  mentioned  above. 


III.  LATENT  STRABISMUS,  with  Particular  Reference 
TO  Divergent  Squint. 

By  latent  strabismus  is  understood  a  disturbance  of  the  muscular 
equilibrium,  which  is  suppressed  for  the  sake  of  binocular  single 
vision.  There  may  be  either  convergent,  divergent,  upward,  or 
downward  squint.  Latent  divergent  squint  is  by  far  the  common- 
est. Occasionally  divergence  and  convergence  may  be  associated, 
convergence  for  distance  and  divergence  for  near.  Three  points 
must  be  satisfied  to  make  the  squint  latent : — 

(i)  Both  eyes  must  be  placed  correctly  when  they  are  used  for 
looking  at  an  object ; 

(2)  One  eye  must  deviate  when  it  is  excluded  from  vision  by  cov- 
ering it ; 

(3)  There  must  be  no  restriction  of  the  muscular  excursion. 

Latent,  and  especially  divergent  squint,  causes  at  first  no  symp- 
toms, but  as  the  deviation  increases  the  symptoms  of  "  muscular 
asthenopia  "  {p.  j68)  appear ;  they  finally  disappear  in  turn  as  latent 
squint  becomes  manifest. 

Causes. — In  some  cases  latent  squint  depends  upon  refractive 
errors  (/>.  443).  Divergence  is  quite  frequently  the  result  of  myopia. 
But  latent  divergent  squint  is  no  rarity  in  emmetropia  or  even  in 
hyperopia.  The  reason  for  it  may  be  found  in  a  weakness  of  the 
recti  interni,  and  many  authors  designate  latent  divergent  squint  as 
insufficiency  of  the  interni.  That  weakness  is  actually  present  is 
seen  by  the  increase  of  the  latent  squint  when  there  are  such  con- 
ditions as  physical  exhaustion,  lack  of  sleep,  indulgence  in  alcohol, 
or  illness  of  any  kind,  which  reduce  the  tone  and  energy  of  the 
whole  body.  Whether  this  weakness  is  of  the  muscles,  or  of  the 
nervous  impulse  to  them,  is  a  disputed  point.  That  it  is  rather  a 
nervous  trouble  is  suggested  by  the  fact  that  the  internal  recti  still 
perform  their  function  to  the  full  extent  of  peripheral  excursions. 

Treatment. — Every  latent  squint  does    not   cause   symptoms. 

Very  high  degrees   are  occasionally  found,  which  dwindle  to  very 

slight  degrees  when  the  fixation  object  is  approached  to  the  eye. 

In  such  cases  treatment  is  unnecessary.     But  if  latent  squint  and 

29 


450  DISTURBANCES    IN    THE    MOVEMENTS    OF   THE    EYES. 

symptoms  of  asthenopia  (/.  j68)  exist  side  by  side,  it  is  unwise  to 
conclude  at  once  that  there  is  any  causal  relationship  between  the 
two,  but  rather  that  asthenopic  symptoms  more  commonly  depend 
upon  refractive  errors  than  upon  latent  squint.  If  refractive  errors, 
conjunctival  {p.  i^j)  and  retinal  asthenopia  (/,  J07)  can  be  ex- 
cluded, or  if  the  connection  between  symptoms  and  squint  are 
made  undoubted  by  the  nature  of  the  patient's  complaint  (occa- 
sional diplopia,  disappearance  of  distress  when  one  eye  is  closed), 
then  treatment  should  be  tried  by  the  prescription  of  suitable 
glasses.  In  the  divergent  squint  of  myopia  the  neutralizing  con- 
cave lenses  often  suffice,  since  they  demand  accommodative  effort 
and  thereby  increase  the  instinct  to  convergence,  while  they  also 
admit  of  work  at  a  greater  distance,  which  implies  a  less  claim  on 
convergence.  If  this  remedy  is  not  sufficient,  or  if,  on  account  of 
emmetropia  or  hyperopia,  is  not  suitable,  we  must  abandon  the 
attempt  to  produce  normal  convergence,  and  resort  to  the  use  of 
prismatic  lenses  (Fi£^.  jj,  p.  gi)  in  order  to  bring  about  binocular 
fusion  with  a  relatively  divergent  position.  For  example,  suppose 
an  emmetrope  has  a  latent  divergent  squint  at  the  usual  reading 
distance  of  jo  cm.,  and  that  this  squint  can  be  neutralized  by  a 
prism  of  8°  base  inward ;  then  with  glasses  having  a  prism  of  ^° 
on  each  side  the  patient  will  be  enabled  to  read  continuously,  with- 
out effort  at  fusion,  at  jo  C7n.  distance.  If  the  patient  wears  glasses 
on  account  of  myopia  or  hyperopia,  a  prismatic  effect  may  be  added 
to  the  lenses  by  giving  them  a  greater  or  smaller  distance  apart 
than  the  pupillary  interval  calls  for.  Suppose  a  patient  to  have 
myopia  of  ^.o  D,  the  neutralizing  lenses  of  ^.oZ>  will  diminish  the 
latent  divergent  squint,  but  will  not  altogether  overcome  it ;  but  if 
the  lenses  are  placed  so  far  apart  that  the  patient  must  look  through 
the  inner  half  of  them,  the  effect  becomes  that  of  prisms  in  the 
position  of  abduction,  the  effect  being  greater  the  nearer  he  looks 
through  the  edge  of  the  glass.  It  must  be  kept  in  mind,  however, 
that  the  dispersing  power  of  the  edge  of  a  lens  is  greater  than  that 
of  the  center.  By  testing  with  A.  Graefe's  equilibrium  test  (/.  g2), 
the  suitable  distance  for  the  glasses  may  be  decided  on. 

It  is  hardly  advisable  to  prescribe  prismatic  lenses  stronger  than 
<^°,  since  the  glasses  are  then  too  heavy  and  the  chromatic  aberra- 
tion too  strong.  If  the  squint  becomes  more  pronounced  than  cor- 
responds to  a  prism  of  6"°,  an  operation  must  be  performed  to  allow 
the  externus  to  retract  by  section  of  its  tendon.     If  the  muscle 


TREATMENT.  45 1 

retracts  it  obviously  grows  weaker  and  the  question  comes  up 
whether  the  improved  convergence  for  near  objects  may  not  have 
been  obtained  at  the  cost  of  diplopia  when  looking  at  distant  objects 
on  the  side  of  the  retracted  muscle.  The  question  may  be  answered 
as  follows :  In  looking  at  distant  objects,  parallelism,  but  never 
divergence,  of  the  visual  axes  is  necessary ;  the  capability  for  real 
divergence — facultative  divergence — may,  therefore,  be  sacrificed 
by  retraction  of  one  or  both  externi  without  causing  any  disadvan- 
tage to  the  patient.  The  capability  for  real  divergence  is  measured 
by  the  strongest  prism  in  the  position  of  abduction  (base  toward 
the  nose)  with  which  binocular  fusion  can  be  maintained  continu- 
ously and  without  effort.  The  approximate  equality  between  facul- 
tative divergence  for  distant  objects  and  insufficiency  when  looking 
at  near  objects  (both  being  measuredby  prisms)  gives  a  clue  for  the 
successful  resort  to  tenotomy.  For  example,  suppose  that  diver- 
gence equal  to  a  prism  of  i6°  is  possible  for  distant  objects,  and  at 
reading  distance  an  equilibrium  with  prism  of  20°  in  the  position 
of  abduction  is  established;  we  may,  without  further  investigation, 
perform  a  tenotomy  on  one  externus,  since  experience  teaches  that 
the  final  result  of  the  operation  is  about  equal  to  the  action  of  a 
prism  of  16° .  Parallelism  of  visual  axes  will  then  be  possible  for 
distant  objects,  while  for  near  objects  there  will  be  a  latent  diverg- 
ence oi  ^° ,  which  may  be  tolerated  without  any  trouble,  or  can  be 
corrected  by  prismatic  glasses  of  ^°  on  each  eye. 

If  the  conditions  are  less  favorable,  that  is,  if  the  facultative  diverg- 
ence is  small,  or  at  least  smaller  than  the  insufficiency  for  near 
objects,  it  is  better  to  advance  an  internus  without  performing 
tenotomy  of  the  externus  at  the  same  time.  There  is  thus  no  loss 
but  rather  a  gain  in  the  range  of  movement. 

The  operation  itself  is  very  simple,  but  success  may  be  difficult 
to  achieve  because  the  difference  between  the  immediate  and  final 
results  of  the  operation  varies  greatly  in  individuals.  The  most 
important  data  for  judging  of  the  condition  immediately  after  the 
operation  are : — 

(i)  The  amount  of  restriction  of  movement,  and 

(2)  Equilibrium  in  the  "  position  of  election." 

This  term  was  used  by  v,  Graefe  to  describe  the  direction  of 
vision  75°  toward  the  side  of  the  eye  not  tenotomized,  and  75° 
below  the  horizon.  At  this  position,  and  with  the  fixation  point  at 
least  J  m.  distant,  equilibrium  will  be  maintained  immediately  after 


452  DISTURBANCES    IN   THE    MOVEMENTS    OF    THE    EYES. 

the  operation,  that  is,  there  will  be  neither  convergent  nor  divergent 
squint.  The  restriction  of  movement  in  the  tenotomized  eye  should 
amount  to  j  or  at  most  6.j  mm.,  according  to  the  amount  of  facul- 
tative divergence ;  a  greater  restriction  would  require  a  conjunctival 
suture  to  overcome  the  result  proportionately. 

The  final  outcome  of  the  operation  for  latent  squint  is  better  than 
it  is  in  that  for  concomitant  squint,  because  the  desire  for  binocular 
single  vision  is  present  in  latent  squint  and  acts  as  an  important 
factor  in  reestablishing  the  normal  muscular  relations. 

[Heterophoria. — By  reading  the  two  preceding  sections  and  the 
paragraphs  on  the  methods  of  examination  {p.  p2),  it  will  be  seen 
that  the  condition  of  squint  is  closely  allied  to  heterophoria,  and 
that  the  latter  may  pass,  by  nearly  imperceptible  gradations,  into 
the  former.  There  is,  however,  one  distinction  that  must  be  care- 
fully made  :  Squint  may  always  be  detected  objectively  by  the  ob- 
server, and  it  sometimes  annoys  the  patient  by  the  production  of 
diplopia,  although  in  concomitant  squint  he  easily  neglects  the  im- 
age in  one  eye ;  but  heterophoria  can  never  be  detected  objectively, 
the  patient  is  never  aware  of  diplopia,  and  there  is  no  suppres- 
sion of  the  image  in  either  eye.  Squint  is,  therefore,  a  condition 
often  detected  by  the  patient,  heterophoria  a  condition  diagnosticated 
only  by  the  ophthalmologist. 

The  causes  of  heterophoria  are  the  same  as  those  given  for  latent 
squint  {p.  44p),  although  the  tendency  of  the  visual  lines  may  be 
either  outward  (exophoria),  or  inward  (esophoria),  or  upward  and 
downward  (hyperphoria). 

Some  confusion  may  arise  by  finding  heterophoria  of  one  kind  for 
near  work,  and  of  another  kind  for  far  work ;  but  it  is  best  to  treat 
only  that  kind  causing  the  greater  trouble.  In  exophoria  headache 
and  eye-strain  are  most  intense  after  near  work,  but  the  power  of  ac- 
commodation may  be  increased.  The  ability  to  overcome  adduct- 
ing  prisms  varies,  but  is  usually  quite  pronounced.  In  esophoria, 
headache  and  eye-strain  are  most  apt  to  appear  after  excessive  use 
of  the  eyes  in  distant  work,  such  as  visits  to  the  theater  or  picture 
gallery,  and  after  long  rides  in  the  cars  ;  the  power  of  accommoda- 
tion may  be  lessened,  while  the  ability  to  overcome  abducting 
prisms  is  usually  pronounced.  In  liyperphoria,  all  sorts  of  condi- 
tions may  be  present,  and  the  statements  of  the  patient  may  be 
unsatisfactory  and  confusing.  There  is  here  more  amblyopia, 
however,  and  more  muscular  or  nervous  irritation  manifested  by 


HETEROPHORIA.  453 

spasm  of  lids,  twitching  of  facial  muscles,  neuralgia,  and  lacrima- 
tion  ;  while  the  ability  to  overcome  a  prism  (base  either  up  or  down) 
is  sure  to  be  increased. 

Treatment  naturally  divides  itself  into — 

(i)  General, 

(2)  Optical,  and 

{3)  Operative. 

(/)  Every  element  which  may  impair  visual  acuity  or  keep  the 
patient's  health  below  par  must  be  persistently  combated.  Rest 
to  the  eyes,  atropin,  electricity  locally  applied,  change  of  occupa- 
tion and  surroundings, — all  have  their  place. 

{2)  Optical  treatment  implies  more  than  the  correction  of  refrac- 
tive errors,  which  must,  of  course,  be  the  initial  therapeutic  meas- 
ure, although  it  not  infrequently  happens  that  the  symptoms  of 
heterophoria  disappear  after  the  eyes  have  been  relieved  of  the 
strain  from  ametropia.  Should  these  symptoms  continue,  the  use 
of  prisms  should  be  immediately  tried  ;  prisms  may  be  prescribed 
either  to  be  worn  constantly,  or  to  be  used  as  a  means  of  exercise. 
In  the  former  case,  the  desired  result  may  be  obtained  either  by 
adding  the  prismatic  effect  to  correcting  lenses  by  decentering,  or 
by  adding  an  actual  prismatic  form  to  the  lenses  prescribed.  In 
the  latter  case,  the  patient  is  treated  by  graduated  prismatic  exer- 
cise at  the  physician's  office,  or  he  is  given  prisms  of  increasing 
power  which  he  can  use  at  home  to  develop  the  weak  muscle  by 
strengthening  the  impulse  to  overcome  them.  "There  can  be  no 
doubt  that  ample  experience  has  shown  the  helpfulness  of  weak 
(/°  to  5°)  prisms  continuously  worn  for  moderate  degrees  of  mus- 
cular error,  and  this  method  should  precede  the  use  of  gymnastic 
prisms  or  of  the  various  other  palliative  measures.  In  giving 
prisms,  the  rule  may  be  formulated  that  the  base  should  be  placed 
toward  the  image  whose  position  is  to  be  corrected  ;  this  corre- 
sponds to  the  weak  muscle,  provided  the  physiological  or  func- 
tional activity  of  the  muscle  is  regarded.  The  apex  of  the  prism 
like  a  knife  edge  indicates  the  muscle  which  should  be  weakened, 
and  the  base  denotes  the  muscle  to  be  strengthened  "  (Noyes). 
But  in  no  individual  case  can  an  inflexible  rule  be  applied. 
For  a  weakness  of  adduction  (exophoria)  prisms  (base  in)  would 
seem  a  priori  to  be  indicated,  but  the  expected  result  is  not  always 
obtained,  while  in  rare  cases  the  very  opposite  prismatic  effect 
(base  out)  has  given  relief     The  same  may  be  said  of  weakness  of 


454  DISTUKBASCES   IN   THE   MOVEMENTS  OF  THE   EYES. 

abduction  (esophoria) ;  prisms  (base  out)  are  indicated,  but  do  not 
always  relieve,  while  the  opposite  prismatic  effect  (base  in)  amelio- 
rates the  distress.  It  is  probable  that  when  such  contradictor^' 
results  are  obtained  there  will  be  found  exophoria  for  distant,  and 
esophoria  for  near  work,  and  that  the  relief  is  experienced  because 
the  patient  really  uses  his  eyes  most  in  the  position  for  which  the 
prisms  meet  the  indication  according  to  the  rule.  Every  case, 
therefore,  must  be  treated  on  its  merits,  and  neither  examination 
nor  treatment  can  be  said  to  be  complete  until  every  possible  \'aria- 
tion  in  the  working  power  of  the  muscles  has  been  thoroughly 
tested, 

(3)  Operative  treatment  consists  of  the  mechanical  (surgical) 
weakening  of  the  over-strong  muscle  by  a  tenotomy.  Such  an 
operation  may  be  total,  the  same  as  is  performed  for  strabismus 
{p.  446)^  or  a  graduated  tenotomy,  in  which  the  effort  is  made  to 
restore  equilibrium  by  section  of  a  few  fibers  at  the  insertion  of  the 
tendon,  A  tenotomy  for  heterophoria  does  give,  in  selected  cases, 
the  most  brilliant  results,  but  the  surgeon  should  alw^ays  remember 
that  operative  interference  is  the  treatment  of  last  resort,  not  to  be 
undertaken  till  all  other  means  have  failed ;  that  however  favorable 
the  momentary  results  may  be,  there  is  apt  to  follow  them  a  distress- 
ing diplopia  due  to  weakness  of  the  muscle  which  was  originally 
too  strong ;  and  that  he  must  be  ready,  at  the  time  of  operating,  to 
control  his  tenotomy,  either  by  a  conjunctival  suture  {p.  447),  or  by 
a  supplementary  tenotomy  of  the  muscle  which  becomes  over-active 
after  the  primary  tenotomy.  For  these  reasons  it  is  wise  for  him  to 
adhere  to  the  following  rules :  always  operate  with  a  local  anesthetic 
only  (cocain) ;  sever  the  tendon  at  its  scleral  attachment,  rather  than 
the  muscular  fibers  ;  divide  the  total  result  wished  for  between  the 
two  eyes,  so  that  a  muscle  of  each  eye  bears  only  half  the  correction ; 
make  repeated  examinations  during  the  operation  to  see  when  the 
heterophoria  has  disappeared ;  and  be  ready  to  correct  an  exag- 
gerated result  at  once,  by  a  conjunctival  suture,  remembering  that 
too  radical  an  operation  may  have  the  0(^>osite  effect  to  that  which 
he  seeks  to  correct,  while  it  is  always  easier  to  repeat  the  first 
operation  on  the  same  muscle  than  to  perform  a  second  operation 
on  its  antagonist. — H.] 


NYSTAGMUS.  455 

IV.  NYSTAGMUS. 

Spasmodic,  involuntary,  jerking  movements  of  the  eyes,  which 
do  not  interfere  with,  but  accompany,  the  normal,  voluntary  move- 
ments of  the  eyes,  are  termed  nystagmus.  Three  forms  are  distin- 
guished according  to  the  direction  of  this  twitching  : — 

(a)  Nystaguiiis  oscillatorius,  twitching  to  the  right  and  left,  hori- 
zontally, or  upward  and  downward,  perpendicularly; 

{U)  Nystagmus  inixtiis,  oblique  twitching  ; 

{c)  NystagjHus  rotatorius,  rotations  about  the  visual  axis.  These 
may  be  quite  distinct,  or  in  combination  with  horizontal,  perpen- 
dicular, or  oblique  twitchings,  so  as  to  produce  directions  of  move- 
ment which,  in  contradistinction  to  {a)  and  (J))  are  in  no  sense  phy- 
siological. 

There  is  often  squint  along  with  nystagmus.  Often,  too,  there 
is  noticeable  a  moderate  shaking  of  the  head  in  the  same  direction 
and  with  uniform  speed  with  the  nystagmus.  This  shaking  of  the 
head  has  been  held  to  be  a  compensatory  movement  for  the  nys- 
tagmus, although  a  compensation  for  an  eye  movement  to  the  right 
by  an  equally  strong  head  movement  to  the  left  cannot  be  demon- 
strated in  individual  cases,  on  account  of  the  rapidity  with  which 
they  are  made. 

In  certain  diseases  nystagmus  changes  remarkably  both  in  rapid- 
ity and  character  of  the  movements ;  if  the  patient  knows  he  is 
closely  watched,  or  if  he  labors  under  any  excitement,  the  phenom- 
ena are  increased,  while  during  sleep  or  narcosis  they  are  lessened 
or  altogether  stopped.  Many  patients  can  themselves  inhibit  the 
movements  by  taking  some  definite  position  for  their  eyes,  say  a  pro- 
nounced convergence.  Many  healthy  patients  can  voluntarily  pro- 
duce a  nystagmus.  This  disorder  may  be  divided  into  three  classes 
according  to  the  causes  : — 

(rt)  Nystagmus  from  ^Veak  Sight  in  Both  Eyes. — This  is  the 
commonest  form.  It  begins  in  early  childhood  as  the  result  of  cor- 
neal or  lens  opacities,  or  of  astigmatism,  of  microphthalmos,  of 
amblyopia  without  cause.  Such  pathological  conditions  cannot  be 
a  matter  of  indifference  for  position  and  movement  of  the  eyes  in 
early  childhood,  since  an  exact  binocular  fifsion  must  be  of  decided 
significance  in  the  development  of  normal  eye  movements.  This 
amblyopia  does  not,  however,  explain  the  nystagmus  completely, 
since  there  are  cases  of  nystagmus  without  amblyopia,  and  cases  of 


456  DISTURBANCES    IN    THE    MOVEMENTS    OF   THE    EYES. 

bilateral  amblyopia  without  nystagmus.  There  must  be  some  fac- 
tor which  influences  the  eye  muscles  themselves;  an  indication  for 
this  is  found  in  the  fact  that  at  one  time  the  external  and  internal 
recti  muscles,  and  at  another  time  the  elevator  and  depressor  mus- 
cles, are  to  be  blamed  for  the  nystagmus  ;  while  another  fact  must 
be  noticed,  namely,  that  certain  visual  directions  are,  by  means  of 
corresponding  movements  of  the  head,  preferably  used  by  the 
patient,  because  all  other  directions  are  more  difficult  for  him. 

This  first  form  of  nystagmus  causes  no  trouble,  and  especially  no 
apparent  movement  of  the  object  looked  at;  therefore  no  treatment 
is  needed  unless  it  be  to  improve  the  visual  acuity. 

{b)  Nystagmus  of  miners  comes  in  paroxysms,  and  is  accom- 
panied by  apparent  movement  of  the  object  looked  at,  and  by  ver- 
tigo. These  paroxysms  are  caused  by  exhaustion  from  trying  to 
see  in  an  insufficiently  lighted  space  (coal  shaft),  and  from  uncom- 
fortable positions  of  the  eyes  like  exaggerated  elevation,  less  often 
exaggerated  depression  of  the  visual  plane. 

The  disease  is  to  be  considered  as  a  paresis  of  the  levator  muscles 
due  to  overstimulation,  so  that  they  contract  only  spasmodically. 
This  paresis  is  favored  by  everything  that  tends  to  make  work  for 
the  eyes  under  such  circumstances  difficult,  such  as  poor  vision 
insufficiency  of  the  interni,  or  physical  prostration. 

The  character  of  eye  movement  in  miners'  nystagmus  is  usually 
a  circular  or  elliptical  rotation.  This  may  be  demonstrated  by 
means  of  a  "  reflection  test:  "  a  luminous  point  in  a  dark  room  will 
appear  to  the  patient  during  an  attack  as  a  circle  or  an  ellipse,  for 
the  same  reason  that  a  luminous  point  rapidly  revolved  appears  as 
a  circle  to  the  healthy  person.  The  distress  is  often  so  great  that 
the  patient  must  abandon  his  vocation.  A  successful  treatment, 
apart  from  simple  rest,  has  not  yet  been  devised. 

[c)  Nystagmus  from  brain  disease  has  only  symptomatic  sig- 
nificance. It  is  of  especial  importance  in  the  diagnosis  of  multiple 
sclerosis,  that  cerebro-spinal  disease  characterized  by  the  appearance 
of  numerous  gray,  fibrillary  connective-tissue  foci  in  brain  and  cord. 
The  three  important  signs  of  this  disease  are  : — 

(i)  "Intention  trembling" — appearing  during  voluntary,  inten- 
tional movements ; 

(2)  *'  Scanning  speech  ;" 

(3)  Nystagmus,  which  may  be  analogous  to  intention  trembling, 
since  it  sets  in  during  fixation  and  during  intentional  eye  movements. 


DISEASES    OF   THE    ORBIT.  457 

DISEASES    OF   THE    ORBIT. 

INTRODUCTION. 

In  most  cases  of  diseases  of  the  orbit  there  is  exophthalmos.  This 
term  implies  a  protrusion  of  the  eyeball  outside  its  natural  position 
in  the  orbit.  This  depends  upon  a  restriction  in  the  space  within, 
either  because  the  eye  is  too  large  for  the  orbit,  as  the  "  pop-eye  " 
of  myopia  (/.  j^p),  or  because  the  otherwise  normal  contents  of  the 
orbit  has  increased,  such  as  the  fat  tissue  in  general  adiposity,  and 
the  quantity  of  blood  if  the  vessels  are  dilated,  or  because  bloody, 
serous  or  purulent  exudations  crowd  the  eyeball  forward. 

The  opposite  of  exophthalmos,  retraction  of  the  eye  within  the 
orbit,  enophtJialmos,  is  at  times  observed.  It  depends  upon  absorp- 
tion of  the  orbital  fat  or  upon  decrease  in  blood  contents  of  the 
orbital  vessels,  or  upon  great  loss  of  fluid  from  the  body  resulting 
from  intense  purging,  as  in  cholera. 

It  is  not  quite  clear  to  me  how  enophthalmos  depends  upon  disappearance  of  the  orbital 
fat.  We  often  see  old  persons  who  have  grown  so  thin  and  "hollow-eyed"  that  the 
finger  can  be  pushed  in  deep  between  the  eyeball  and  wall  of  the  orbit,  but  notwithstand- 
ing all  this,  there  is  no  trace  of  enophthalmos  1  As  the  eyeball  lies  in  the  orbit,  the  fat 
is  only  a  filling,  while  the  connective  tissue  is  the  net  in  which  the  eye  is  suspended. 

To  measure  the  amount  of  exophthalmos  H.  Cohn  and  others 
have  devised  special  instruments.  The  exophthalmometer  has  not 
become  popular,  because  the  position  of  the  eyeball  changes  within 
physiological  limits  so  markedly  that  a  statement  that  the  corneal 
apex  is  so  many  millimeters  in  front  of  a  certain  point  on  the  edge 
of  the  orbit  cannot  be  taken  to  mean  that  a  pathological  degree  of 
exophthalmos  is  present.  A  comparison  between  the  two  eyes  is 
of  more  value.  This  is  obtained  by  measuring  how  many  milli- 
meters the  corneal  apex  of  each  eye  lies  behind  the  same  point, 
say  the  bridge  of  the  nose.  There  may  be  differences  here,  of 
course,  depending  upon  asymmetry  of  the  cranium,  and  these 
would  have  no  pathological  significance.  As  a  rule,  a  simple  guess 
will  answer.  It  must  be  remembered,  however,  that  a  wide  pal- 
pebral fissure  may  simulate  exophthalmos,  a  narrow  fissure  or  a 
moderate  ptosis  may  simulate  enophthalmos. 


458  DISEASES    OF   THE   ORBIT. 

I.  INJURIES. 

(a)  Injury  by  a  blunt  weapon  may  cause  a  fracture  of  the  bony 
wall  of  the  orbit.  On  account  of  the  concealed  position  of  the 
bones  of  the  orbit,  the  well-known  signs  of  fracture — abnormal 
motility,  pain  on  pressure,  crepitation — can  be  made  out  only  in 
exceptional  cases.  As  a  rule  we  must  be  content  with  the  history 
of  the  case  and  the  demonstration  of  the  presence  of  blood  in  the 
orbital  cavity.  This  will  be  evidenced  by  exophthalmos  and,  per- 
haps, by  subsequent  subconjunctival  and  palbebral  hemorrhage 
(/.  146).  The  diagnosis  is  established  when  the  fracture  is  asso- 
ciated with  one  of  an  adjacent  air  space  (the  nasal,  temporal  sinus 
or  the  antrum  of  Highmore),  which  produces  an  emphysema  of 
the  conjunctiva  and  lids,  or  when  the  injury  to  the  orbit  leads  to 
nasal  hemorrhage ;  in  this  latter  case  we  may  conclude  that  the 
fracture  involves  the  median  wall  of  the  orbit.  Injuries  by  a  blunt 
weapon  not  infrequently  result  in  inflammation  of  the  bone  or 
periosteum.  This  is  especially  the  case  in  scrofulous  or  syphilitic 
individuals. 

Fractures  of  the  orbital  wall  may  be  occasioned  without  direct  contact  of  the  weapon, 
as  from  a  fall  upon  the  back  of  the  head,  for  example.  In  such  cases  life  is  so  endan- 
gered by  other  injuries,  such  as  fractures  at  the  base  of  the  skull,  that  the  effect  on  the 
eye  becomes  subordinate. 

Quite  exceptionally  enophthalmos  instead  of  exophthalmos  results  from  injury  to  the 
orbit.  This  "  enophthalmos  traumaticus  "  is  explained  in  various  ways.  It  seems  to 
me  most  probable  that  the  cause  is  to  be  sought  for  in  a  laceration  or  rupture  of  connect- 
ive-tissue fibers  that  pass  from  Tenon's  capsule  to  different  points  of  the  orbit,  and  act  as 
suspensory  ligaments  of  the  eyeball. 

(d)  Injury  by  a  penetrating  weapon  always  leads  to  more  or  less 
laceration  of  the  soft  parts.  The  most  common  objects  causing 
injury  are  pitchforks,  the  horns  of  cattle,  umbrellas,  canes,  knives, 
and  shot  of  all  kinds.  In  many  cases  the  diagnosis  is  established 
by  finding  adipose  tissue  exposed  in  a  conjunctival  wound.  In 
other  cases  the  injury  may  be  diagnosticated  from  the  nature  and 
extent  of  the  disturbance  of  eye  movement.  The  character  of  the 
weapon  causing  the  injury  must  be  considered  in  deciding  whether 
it  has  remained  wholly  or  in  part  within  the  wound.  To  avoid 
error,  it  is  best  to  introduce  the  point  of  the  finger  between  eye 
and  orbital  wall,  and  to  explore  the  whole  orbit.  If  touch  reveals 
nothing,  the  wound  should  be  sounded,  but  with  most  careful  anti- 


LUXATIO    BULBI PERIOSTITIS   ORBIT/E,  459 

sepsis.  If  the  foreign  body  has  carried  any  germs  with  it,  there 
is  inflammation,  suppuration,  and  orbital  abscess  to  be  feared. 

Treatment. — Injuries  by  a  blunt  weapon  are  to  be  treated  by 
rest  and  cooling  compresses.  The  wound  must  be  disinfected  and 
bandaged.  All  foreign  bodies  must  be  removed.  Since  they  often 
lodge  in  the  bony  wall  of  the-orbit,  the  extraction  sometimes  de- 
mands the  use  of  strong  forceps,  but  in  case  the  foreign  body  lies 
at  the  roof  of  the  orbit,  the  proximity  of  the  brain  should  never  be 
forgotten.  Small  aseptic  foreign  bodies,  like  shot,  usually  heal  en- 
capsulated ;  they  should  not,  therefore,  be  removed  without  good 
reasons  for  it. 

(<:)  Luxatio  Bulbi. — If  a  wedge-shaped  foreign  body,  the  thumb, 
for  example,  is  crowded  between  eyeball  and  external  wall  of  the 
orbit,  it  can,  by  using  the  external  wall  as  fulcrum,  squeeze  the  eye- 
ball out  of  its  bed.  In  parts  of  Bavaria  and  America  (Virginia, 
among  the  negroes)  this  device  is  resorted  to  by  contestants  to  ren- 
der the  opponent  incapable  of  fighting.  In  Uganda,  in  Central 
Africa,  masters  make  their  slaves  one-eyed  in  this  way,  the  one- 
eyed  appearance  serving  as  a  livery.  After  the  luxation  the  eye 
lies  in  front  of  the  orbit,  and  the  lids  are  closed  in  a  spasm  behind 
it.  The  muscles  are  somewhat  lacerated,  and  stretched  so  much 
that  eye  movements  are  impossible.  Vision  is  lost,  either  directly 
through  stretching  of  the  optic  nerve,  or  through  the  anemia  caused 
by  this  stretching.  Treatment  consists  in  reposition  and  bandage. 
Vision  may  return. 

2.  INFLAMMATIONS. 

(a)  Periostitis  Orbitae. — The  disease  attacks  scrofulous  chil- 
dren and  syphilitics,  in  preference.  A  blow  or  a  fall  upon  the 
edge  of  the  orbit  is  usually  the  exciting  cause.  Since  the  upper  outer 
and  the  lower  outer  edges  are  most  exposed  to  injuries,  these 
points  are  most  commonly  the  seat  of  the  inflammation.  The  dis- 
ease begins  with  a  dull  pain  increased  by  pressure  upon  a  certain 
spot  of  the  orbital  edge.  A  swelling  is  gradually  developed,  which 
is  painful,  immovable,  and  strikingly  hard.  The  skin  covering  the 
swelling  is  red  and  edematous.  A  small  portion  of  the  swelling 
now  becomes  soft  and  fluctuates,  and  with  perforation  there  is  an 
escape  of  thin,  watery,  foul-smelling  pus.  If  a  sound  is  introduced 
into  the  fistula,  it  strikes  rough  bone, — caries.     Foul-smelling  pus 


460  DISEASES    OF   THE    ORBIT. 

is  continuously  poured  out  of  the  fistula  till,  after  months  or  years, 
all  necrosed  bone  is  expelled.  Cicatrization  of  the  fistula  involv- 
ing the  skin,  generally  that  of  the  lid,  follows.  Ectropion  and  its 
consequences  result  (/.  /<5j). 

Treatment  must  be  antiphlogistic  at  the  beginning.  Leeches 
to  the  temple  (not  on  the  lid,  see  ^.  14.6)  and  cold  compresses 
may  help  to  "  scatter  "  the  inflammation.  This  expectation  is  not 
unwarranted,  and  the  treatment  may  succeed  if  the  periostitis  is 
syphilitic,  and  is  subsequently  treated  with  mercury  and  iodids. 
If  suppuration  is  unavoidable,  however,  the  treatment  should  be 
with  heat,  incision,  and  drainage — proper  surgical  methods. 

{b)  Orbital  Abscess. — This  distinct  form  of  the  disease  may 
develop  from  a  periostitis  if  the  wall  of  the  orbit  instead  of  its  edge 
is  involved.  With  the  pain  there  is  then  fever,  general  prostration, 
swelling,  and  redness  of  the  lids,  particularly  the  upper  one,  ptosis, 
chemosis  of  the  conjunctiva  bulbi,  exophthalmos,  restriction  in  eye 
movement,dilatationofthe  pupil,  and  visual  disturbance.  The  patient 
has  an  appearance  that  suggests  a  blennorrhea  (/.  iSS^)  or  a  panoph- 
thalmitis (/>.  2^6).  The  lack  of  discharge  from  the  conjunctiva 
excludes  blennorrhea  positively.  The  unimpaired  or  relatively  nor- 
mal condition  of  the  interior  of  the  eye  (to  the  ophthalmoscope)  is 
against  the  diagnosis  of  panophthalmitis.  The  pus  spreading  in  the 
cellular  tissue  of  the  orbit,  with  an  increase  in  all  the  symptoms, 
gradually  makes  its  way  to  the  surface  and  finds  an  opening  either 
into  the  conjunctival  sac  or  upon  the  lids.  As  soon  as  the  pus 
escapes  the  patient  obtains  relief,  but  it  takes  a  long  time  before  the 
normal  condition  is  restored.  An  unfavorable  result  is  obviously 
not  excluded,  since  optic  neuritis,  sloughing  of  the  cornea  and  even 
of  the  whole  eye  may  cause  blindness,  or  if  the  inflammation  reaches 
the  brain,  it  may  end  in  death. 

Not  only  periostitis  orbitae,  but  also  any  suppurative  or  even 
inflammatory  process  in  the  vicinity  of  the  eye,  may  lead  to  abscess 
within  the  orbit.  As  examples  we  have  empyema  of  the  orbit,  sep- 
tic thrombosis  of  a  cranial  sinus  from  caries  of  the  inner  ear,  ulcers 
of  the  nose,  furuncle  and  erysipelas  of  the  face,  and  inflammations 
about  the  roots  of  the  teeth. 

A  third  group  is  the  metastatic  orbital  abscess,  traceable  to  infec- 
tion of  the  general  system  by  glanders,  anthrax,  or  to  pyemia.  In 
the  second  and  third  group  there  is  usually  a  number  of  small 
abscesses  scattered  along  the  orbital  veins. 


DISTURBANCES    OF   THE    CIRCULATION.  46 1 

The  fourth  and  largest  group  embraces  those  cases  in  which  the 
pus-causing  germs  have  been  introduced  on  the  weapon  or  foreign 
body  producing  the  injury,  and  in  preantiseptic  times  on  the  sur- 
geon's instruments,  as  in  squint  operations.  In  some  cases  it  is 
impossible  to  discover  a  direct  cause. 

The  prognosis  depends  upon  the  cause.  Metastatic  orbital 
abscesses  generally  lead  to  death.  In  periostitis  of  the  roof  of  the 
orbit  there  is  always  danger  of  perforation  into  the  cranial  cavity, 
since  the  bone  in  this  region  is  as  thin  as  paper.  In  other  cases  the 
prognosis  is  favorable. 

Treatment  consists  in  finding  the  spot  where  perforation  is  to 
be  expected  and  then  in  incision  and  drainage.  As  a  rule  an  inci- 
sion must  be  made  before  periostitis  can  be  demonstrated  by  prob- 
ine  for  bare  bone. 


3.  DISTURBANCES  OF  THE  CIRCULATION. 
(a)  Pulsating  Exophthalmos. — 

The  internal  carotid  artery,  after  passing  from  the  carotid  canal  in  the  temporal  bone 
and  running  by  the  side  of  the  body  of  the  sphenoid,  enters  the  cavernous  sinus,  a  venous 
space  in  the  substance  of  the  dura  divided  by  fibrous  cords  into  many  compartments  {F/g. 
/j6).  The  artery  lies  on  the  wall  of  this  sinus  and  half  of  its  own  bulk  protrudes  unpro- 
tected into  the  lumen  of  the  sinus.  If  the  carotid  should  be  lacerated  at  this  spot  the 
result  would  be  a  flow  of  blood  into  the  sinus  and  spaces  connected  with  it ;  that  is,  an 
aneurisma  arterio-venosum  would  be  produced. 

The  most  important  connections  of  the  sinus  are  with  the  brain  and  orbit.  Since  the 
cerebral  veins  are  prevented  from  any  noticeable  expansion  by  the  already  well-filled  mem- 
branes of  the  brain,  the  effect  of  an  arterial  hemorrhage  into  the  cavernous  sinus  makes 
itself  felt  in  the  ophthalmic  veins  and  its  branches,  producing  a  pathological  picture  called 
pulsating  exophthalmos.  The  nerves  of  the  orbits  (abducens,  oculomotorius,  trochlearis, 
and  ramus  ophthalmicus  of  the  trigeminus)  also  suffer,  since  they  pass  in  part  through 
the  cavernous  sinus  {_Fig,  ijO),  in  part  above  it. 

Pulsating  exophthalmos  has  the  following  signs :  There  is  ex- 
ophthalmos, usually  with  displacement  of  the  eye  downward,  pre- 
sumably because  the  vena  ophthalmica  inferior  does  not  enter  the 
cavernous  sinus,  or  because  of  its  connections  with  the  veins  in  the 
sphenoidal  fissure  {Fig.  757)  it  is  not  affected  by  the  stasis.  The 
lids  are  red,  swollen,  and  marked  by  dilated  veins  coming  from  the 
vicinity  of  the  eye, — there  is  ptosis.  The  conjunctiva  is  very 
chemotic  and   marked  by  strongly  dilated  veins.     The  cornea  is 


462 


DISEASES    OF   THE    ORBIT. 


normal  or  faintly  cloudy,  and   its  sensitiveness  is  reduced.     The 
pupil  is  dilated  and  rigid  or  at  least  sluggish. 


Carofii 


Nerfus  ocuhnwiJiniis, 
Neryus  trochlearis  - .  _ 
Nerfus  abducens  ■ 

n 

Pirte  branches  of  ti 


f  Spaces  of  i}ie 
'■Sinus  cavermsus 


2fypopAvscs 


Fig.  156. — Frontal  Section  through  the  Sinus  Cavkrnosus.     {After  Merkel,  drawn  by 

L.  Schroeter.) 


Artriliari^ 

A  rf.  a/irtrLs 

////.  //frrymn/i.s  -  - 
0>/ru'uirucating  brn/erA 

Afi  a'n&a/is  retinae 


Jem  oa/A/r/yrt/r/i 
uf/er/or. 


Art.  flp//i/l^/rttOT . 


~-  Art  Lacry'm. 
-Art  jupn/or//ff 
Artfronfnl 

-Ar(.^mouf  n//t 

-Muse,  re ff  sup. 

-Art  ethmoi/fpost 


Vopth.  super 
A^err us  opticus. 


Fig.  157. — The  Veins  of  the  Orbital  Cavity.     {After  Merkel,  drawn  by  L.  Schroeter.) 


If  a  finger  is  placed  on  the  protruding  eyeball,  there  is  felt  a  pulsa- 
tion and  at  times  a  thrill  with  every  heart  beat.  Near  the  eye 
there  may  be  a  pulsating  tumor.     A  moderate  pressure  suffices   to 


PULSATING    EXOPHTHALMOS.  463 

replace  the  eye  within  the  orbit,  but  on   removing  the  finger  the 
former  condition  at  once  reappears. 

The  third  diagnostic  sign  is  discovered  by  means  of  auscul- 
tation on  the  eye,  the  forehead,  or  the  temple.  With  the  pulse 
there  is  also  heard  a  vesicular  murmur  that  fades  away  to  a  faint 
sigh  during  the  diastole  of  the  heart. 

The  ophthalmoscope  shows  a  thinness  of  the  retinal  arteries, 
great  dilatation  and  varicosity  of  the  veins  ;  and  choked  disc  in 
many  instances.  In  spite  of  these  changes  visual  acuity  may  be 
normal,  but  it  is  often  reduced  or  obliterated.  The  patient  com- 
plains of  pain  in  the  orbit,  forehead,  and  temple,  changing  in  sever- 
ity, and  of  subjective  noises  that  may  be  so  loud  as  to  affect  hearing 
and  prevent  sleep.  Compression  of  the  common  carotid  in  the 
neck  may  stop  the  symptoms  at  once,  but,  of  course,  only  so  long 
as  compression  is  maintained. 

What  can  cause  a  rupture  of  the  internal  carotid  within  the  caver- 
nous sinus  ? 

(/)  An  injury,  either  direct,  as  a  puncture  through  the  orbit,  or  a 
penetrating  shot;  or  indirect,  as  a  fracture  at  the  base  of  the  brain  ; 

{2)  Disease  of  the  arterial  wall  (arterio-sclerosis,  syphilis),  which 
yields  to  an  accidental  rise  in  blood  pressure  produced  by  move- 
ment, cough,  or  the  like. 

The  prognosis  is  doubtful.  The  eye  may  be  blinded  by  kera- 
titis neuroparalytica  (p.  2j8),  keratitis  e  lagophthalmo,  or  by 
neuroretinitis  or  ischemia  retinae.  Life  may  be  endangered  by 
severe  and  repeated  nasal  hemorrhages,  or  by  further  changes  in 
the  brain.  The  perforation  in  the  carotid  may,  however,  be  blocked 
by  a  thrombus  and  healing  result. 

Treatment. — What  happens  spontaneously  in  favorable  cases — 
thrombosis  of  the  cavernous  sinus — must  be  produced  if  possible 
by  treatment : — 

(/)  Reduction  of  blood  pressure  in  the  internal  carotid  by  quiet 
living,  rest  in  bed,  restricted  diet,  and  avoidance  of  liquids ; 

(.?)  Interference  with  the  circulation  by 
{a)  Compression,  or 
{b)  Ligation  of  the  common  carotid. 

In  many  cases,  particularly  in  those  resulting  without  injury, 
regulation  of  life,  combined  with  compression,  will  bring  about  a 
cure.  If  the  cause  was  an  injury,  ligation  of  the  common  carotid 
must  be  resorted  to. 


464  DISEASES  OF   THE  ORBIT, 

(/')  Thrombosis  of  the  Ophthalmic  Vein  is  not  a  disease  but  a  symptom.  •  l*here 
are  seplic  nnd  nmnisinatir  tliroml>oscs.  Septic  thromboses  belong  or  rather  lead  to  the 
conditinti  of  orbital  abscess  (/.  460).  The  marasmatic  thromboses  are  but  symptoms  of 
a  sinus  thrombosis,  whicli  is  characterized  by  coagulation  of  blood  within  the  cerebral 
tinuses  extending  outward  from  the  brain  through  the  veins  leading  to  it,  or  protlucing 
symptoms  of  stasis  in  the  Icrritory  of  these  veins.  Stasis  in  the  territory  of  the  ophthal- 
mic vein  may  arise  from  sinus  thromlxisis,  and  this  may  be  assumed  if  other  symptoms 
are  present  as  well,  such  as  general  marasmus  of  the  patient,  disturbance  of  cerebral  func- 
tions, bilateral  appearance  of  the  eye  symptoms,  and  edema  behind  the  ear.  The  dis- 
position to  this  bilateral  involvement  depends  upon  the  fact  that  both  sinuses  are  con- 
nected by  oblique  passages,  and  that  consequently  a  clot  in  one  sinus  can  easily  spread 
into  the  other.  The  involvement  of  the  region  of  the  mastoid  depends  upon  the  fact 
that  the  mastoid  vein  leads  to  the  descending  arm  of  the  transverse  sinus,  which  is  in 
direct  connection  with  the  cavernous  sinus.     Sinus  thrombosis  always  leads  to  death. 

(r)  Exophthalmic  Goiter,  Basedow's  Disease,  Grave's  Dis- 
ease.— Thi.s  must  be  briefly  mentioned  here,  since,  although  it  is 
not  an  essential  disease  of  the  eyes,  it  has  noticeable  eye  symptoms 
of  importance  to  the  diagnosis,  w4iich  often  lead  the  patient  to  con- 
sult the  ophthalmologist  first.  The  disease  has  three  principal 
signs : — 

(/)    Rapid  pulse ; 

(2)   Enlargement  of  the  thyroid  gland  ; 

(?)  Bilateral  exophthalmos. 

The  pulse  beats  loo  or  more  to  the  minute  in  full  bodily  and 
mental  repose,  while  the  least  physical  exertion  or  mental  excite- 
ment may  raise  it  to  140  and  beyond.  The  large  vessels  in  the 
neck  are  dilated  and  have  a  pulsation  that  is  quite  noticeable  in 
comparison  to  the  weak  radial  pulse.  The  area  of  heart  dulness 
is  increased,  the  apex  beat  is  stronger  and  labored. 

The  thyroid  gland  is  moderately  enlarged,  soft,  has  a  visible  and 
palpable  pulsation,  and  shows  a  systolic  murmur  on  auscultation. 
This  may  all  be  taken  as  evidence  that  enlargement  depends  chiefly 
upon  dilatation  of  the  blood-vessels  rather  than  upon  hyperplasia 
of  tissue. 

The  exophthalmos  varies,  not  only  in  different  cases,  but  at  times 
in  the  same  patient.  The  eyes  may  be  pressed  back  into  the  orbits 
by  gentle  pressure,  an  evidence  that  the  cause  of  the  exophthalmos 
is  a  dilatation  of  the  blood-vessels  in  the  orbit.  Even  where  the 
exophthalmos  is  not  remarkable  there  is  a  decided  expansion  of 
the  palpebral  fissure,  and  winking  is  incomplete  and  infrequent,  a 
condition  due  to  lessened  reflex  sensitiveness  of  the  cornea  and 
conjunctiva — Stellwag" s  symptom.     In  looking  downward  the  upper 


EXOPHTHALMIC   GOITER.  465 

lid  does  not,  as  it  normally  should,  descend,  but  lags  behind  and 
the  **  white  of  the  eye  '*  becomes,  therefore,  visible  above  the  cornea, 
giving  the  patient  a  peculiar  appearance — v.  Graefes  srmfttmi.  The 
incompleteness  of  closure  of  the  lid  causes  complaints  and  such 
danger  as  comes  from  irritation  or  inflammation  of  cornea  or  con- 
junctiva. The  exophthalmos  makes  convergence  difficult ;  in  one 
of  my  cases  this  was  the  only  reason  the  patient  gave  for  coming 
to  a  physiciaii.  In  high  degrees  of  exophthalmos  there  is  lag<:^>h- 
thaimos  (/.  i6d),  and  at  times  there  are  disturbances  of  lacrimal 
sccretioo,  it  b«ng  either  too  much  or  too  little.  Besides  the  symp- 
toms in  heart,  neck,  and  eye  there  are  numerous  other  disturbances 
of  the  nervous  and  digestive  systems  which  are  discussed  in  the 
text-books  of  internal  medicine. 

The  nature  of  the  disease  we  may,  with  Friedreich  and  Sattler, 
assume  to  be  an  injury  to  certain  closely  approximate  nerve  cen- 
ters, particularly  the  vagus  nucleus  (heart),  the  vasomotor  centers 
controlling  the  blood-vessels  of  neck  and  head,  and,  finally,  the  cen- 
ters for  the  coordination  between  looking  downward  and  closing 
the  lids,  and  for  reflex  lid  movements.  These  centers  can  be  located 
in  the  gray  matter  of  the  third  and  fourth  ventricles.  The  nature 
of  &e  diaBge  in  these  centers  is  not  yet  known.  The  causes  of 
the  disease  are  as  little  known.  It  has  been  noticed  that  excision 
of  the  thyroid  gland,  or  even  the  production  of  artificial  atrophy  by 
I^Kation  of  its  arteries,  may  either  cure  or.  to  some  extent,  improve 
thfe  disease.  On  this  £act  is  based  the  theory  that  the  cause  of  the 
disease  is  to  be  found  in  a  pathological  secretion  of  the  thyroid,  a 
kind  of  autoinfection.  The  w^hole  matter  is  still  very  obscure,  but, 
according  to  this  theory,  the  involvement  of  the  thyroid  is  the  first 
phenomenoa,  cver\-thing  else  being  results  of  it. 

The  prognosis  is  doubtful.  The  majoritj^  of  cases  recover  after 
an  illness  of  j'ears.  This  is  particularly  true  of  women,  who  are 
also  more  frequently  attacked  than  men.  In  men,  especially  in 
advanced  life,  the  prognosis  is  unfeivorable,  since  the  cfisease  not 
infrequently  leads  to  death  from  exhaustion.  An  acute  course  of 
the  disease  has  been  observed,  ending  in  either  cure  or  death. 

Treatment  consists  in  good  ph\*sical  nourishment,  mental  calm, 

life  in  the  country  or  at  a  sanitarium.     This  is  not  the  ophthalmic 

surgeon's  province ;  he  has  to  do  only  with  the  affections  of  the 

cornea  and  conjunctiva,  with  the  exophthalmos  or  iagophtfaahnos» 

30 


466  DISEASES    OF   THE    ORBIT. 

and  with  the  muscular  asthenopia,  to  the  sections   on  which  the 
student  is  referred. 


4.  TUMORS. 

Every  appreciable  tumor  of  the  orbit  must  cause  an  exophthal- 
mos, and  the  direction  in  which  the  eye  is  displaced  depends  upon 
the  seat  of  the  tumor. 

A  second  symptom  is  disturbance  of  motility,  either  because  the 
tumor  prevents  eye  movements  mechanically,  or  because  muscles 
and  nerves  are  matted  together  and  thereby  prevented  from  func- 
tionating.    Both  conditions  may,  of  course,  occur  simultaneously. 

A  third  symptom  is  disturbance  of  vision ;  not  always  present, 
however.  When  present,  it  is  due  to  pressure  upon  or  involvement 
of  the  optic  nerve,  or  to  retinal  or  choroidal  disease. 

A  fourth  symptom  is  pain.  If  lacking,  it  implies  benignancy  of 
the  tumor  ;  if  present,  either  benignancy  or  malignancy. 

Although  these  four  signs  support  the  diagnosis  of  a  tumor,  this 
is  not  established  until  the  tumor  itself  is  demonstrable  to  the  touch. 

Tumors  of  all  kinds  have  been  observed.  The  most  usual  will 
be  Tnentioned  here.  Tumors  of  the  lacrimal  gland  are  described  on 
p.  i6g. 

(rt)  Tumors  of  the  Orbital  Wall. 

Osteoma  is  a  lumpy,  bony  growth  of  ivory  hardness.  As  a  rule  it  arises  from  the  roof 
of  the  orbit.  The  development  is  slow  and  painless.  The  diagnosis  may  be  made  from 
its  hardness,  immobility,  and  connection  with  the  orbital  wall.  Syphilis  has  been  assumed 
as  cause  in  some  cases.  The  prognosis  is  favorable,  as  far  as  life  is  concerned,  even  if  the 
growth  extends  into  the  orbital  cavity.  The  eyeball  may  be  rendered  useless  by  exoph- 
thalmos or  lagophthalmos.  Treatment  consists  in  inunctions  of  mercurj',  etc. ,  if  syphilis 
is  the  cause.  Extirpation  is  admissible,  according  to  Berlin,  only  when  the  roof  of  the 
orbit — separating  orbit  from  brain — is  not  involved.  If  removal  is  out  of  the  question 
enucleation  of  the  unavoidably  useless  eye  will  save  the  patient  much  distress. 

Encephalocele,  brain  hernia,  is  a  prolapse  of  dura  through  some  congenital  aperture 
between  ethmoid  and  frontal  bones,  or  through  any  congenital  aperture  in  the  orbital 
roof.  This  sac  contains  fluid  or  brain  matter  and  forms  a  tumor  lying,  as  a  rule,  at  the 
inner  upper  angle  of  the  orbit.  The  diagnosis  is  confirmed  if  the  tumor  can  be  dispelled 
by  pressure,  while  at  the  same  time  symptoms  of  pressure  on  the  brain,  such  as  rolling  the 
eyes  and  other  spasms,  are  produced.  Such  a  pathological  condition  leads  sooner  or  later 
to  death.     If  life  is  still  maintained  with  such  a  tumor,  nothing  can  be  done  to  remove  it. 

(b)  Tumors  of  the  Optic  Nerve. 

Myxoma  or  myxosarcoma  is  a  jelly-like  tumor  about  a  pigeon's  or  hen's  egg  in  size. 
The  diagnosis  rests  on  a  slowly  increasing  exophthalmos,  relatively  little  disturbance  of 
motility  (because  the  tumor  is  within  the  funnel  of  the  muscles),  early  blindness  from 


TUMORS    OF   THE    CELLULAR    TISSUE.  467 

papillitis  or  optic  nerve  atrophy,  and  the  discovery  of  a  tumor  near  the  optic  nerve  by 
introducing  the  finger  between  eyeball  and  orbital  wall. 

These  tumors  are  benign  and  even  after  incomplete  removal  are  not  given  to  local 
relapses.  Treatment  consists  in  removal,  with  retention  of  eyeball,  if  possible.  The 
best  method  of  operation  is  Kronlein's  osteoplasty — sawing  through  and  turning  back 
the  temporal  wall  of  the  orbit.  This  permits  full  view  of  the  space  behind  the  eyeball,  so 
that  the  tumor  can  be  shelled  out,  after  which  the  dislodged  wall  of  the  orbit  is  carefully 
replaced. 

[c)  Tumors  of  the  Cellular  Tissue. 

These  are  cysts,  sarcomata,  and  vascular  tumors. 

Among  the  n'sts,  dermoid  and  echinococcus  vesicles  are  relatively  the  most  common. 
Dermoid  cysts  are  always  congenital,  and  are,  therefore,  usually  observed  on  children. 
Their  contents  are  fluid  or  gelatinous  ;  the  presence  of  hairs,  teeth,  and  other  structures 
springing  from  the  epidermic  layer,  proves  that  the  condition  is  one  in  which  the  external 
skin  has  been  turned  in  and  subsequently  incarcerated.  The  diagnosis  of  a  cyst  rests 
upon  the  evidence  of  an  orbital  tumor  and  fluctuation. 

Echinococcus  cyst  is  distinguished  from  the  dermoid  only  by  the  fact  that  the  former 
is  not  congenital,  grows  faster,  causes  pain,  and  endangers  the  eye. 

Treatment  consists  in  extirpation. 

Vascular  tumors  are  telangiectasia,  cavernous  angiomata,  and  aneurysms. 

Telangiectasia  of  the   orbit  is  the  same  as  a  "  birth  mark  "  on  skin  or  lid  (/.  167). 

The  caz'ernoiis  angioma  lies  within  the  funnel  of  the  muscles,  and  therefore  does 
little  damage  to  eye  movements.  The  essential  sign  of  it — apart  from  those  characteriz- 
ing all  tumors — is  the  changing  increase  and  decrease  in  size,  noticed  continuously  or 
produced  at  will,  by  bending  forward,  for  example,  or  by  forced  expiration ;  in  short,  by 
anything  that  retards  the  return  of  blood  from  the  head.  The  exophthalmos  accompany- 
ing it  can  be  overcome  by  pressure  on  the  eyeball.  Prognosis  is  good  so  far  as  concerns 
life,  but  doubtful  for  the  eye.  However  long  the  tumor  may  take  in  growing,  the  result 
is  sure  to  be  pressure  atrophy  of  the  optic  nerve,  or  inflammation  of  the  eye.  Treatment 
must  be  extirpation. 

Aneurysms  have  the  above  symptoms  with  the  addition  of  pulsation.  If  they  are  quite 
large,  they  may  produce  the  picture  of  pulsating  exophthalmos.  In  such  a  case  the  same 
treatment  is  advisable  {p.  463). 

Sarcomata  are  usually  within  the  eyeball  (/.  ^97)  or  on  its  anterior  surface  (/.  218'), 
and  have  therefore  been  already  mentioned  ;  a  genuine  orbital  sarcoma  is  a  great  rarity. 
Its  malignancy  is  betrayed  by  its  rapid  growth,  pain,  and  early  effect  upon  health.  There  is, 
besides,  a  disturbance  quite  out  of  proportion  to  the  size  of  the  tumor,  due,  of  course,  to 
involvement  of  the  muscles  within  the  growth  ;  an  innocent  tumor  merely  pushes  the 
muscles  to  one  side  and,  therefore,  affects  movement  only  mechanically.  The  prognosis 
is  bad, — the  more  unfavorable  the  younger  the  patient  and  the  richer  in  cells  the  tumor  is. 

Treatment  consists  in  evisceration  of  the  orbit,  exenteratio  orbitse  ;  the  operation  is 
perfonned  as  follows  :  the  external  canthus  is  split  and  the  lids  drawn  as  widely  apart  as 
possible,  in  order  totget  space.  A  knife  is  then  passed  around  the  entire  bony  circum- 
ference of  the  orbit,  and  the  orbital  periosteum,  beginning  at  the  wound,  is  loosened  by 
raspatorium  or  chisel ;  this  is  continued  until  the  entire  periosteum  with  all  its  contents 
is  separated  from  the  bony  wall,  being  left  adherent  only  at  the  apex  of  the  orbit.  A 
scissors  curved  on  the  flat  is  then  introduced,  and  the  stump  of  this  mass  of  tissue  is  cut 
off  close  to  the  bone.  Hemorrhage  from  the  ophthalmic  artery  is  best  stopped  by  the 
actual  cautery.  If  the  lids  are  involved  in  the  growth,  the  first  incision  should  be  carried 
beyond  it  into  healthy  skin,  and  lids  removed  with  orbital  contents. 


APPENDIX  A. 


ABBREVIATIONS  USED  IN  OPHTHALMOLOGY. 

(Gould's  Illustrated  Dictionary,  page  x:.) 


Acc. 

.  Accommodation. 

L.  M. 

.  Light  Minimum. 

Ah. 

.  Hyperopic  Astigmatism. 

M.  . 

.  Myopia,  Myopic. 

Am. 

.  Myopic  Astigmatism. 

m.    . 

.  Meter. 

As. 

.  Astigmatism. 

mm. 

.  Millimeter. 

Ax. 

Axis. 

O.  D. 

.  Oculus  dexter — Right  Eye. 

B.D. 

.  Base  (of  prism)  down. 

O.  S. 

.  Oculus  sinister — Left  Eye. 

B.  I. 

"       "       "       in. 

O.U. 

.  Oculi  utrique — Both  Eyes., 

B.  O. 

.      "       "       "       out. 

P.p. 

.  Punctum  proximum,  Near  Point 

B.U. 

•      "       "      "       up- 

P.  r. 

.  Punctum  remotum,  Far  Point. 

cm. 

.  Centimeter. 

R.  E. 

.  Right  Eye. 

Cyl. 

.  Cylinder,  Cylindric  Lens. 

Sph. 

.  Spheric,  Spheric  Lens. 

D.    . 

.  Diopter. 

Sym. 

.  Symmetric. 

E.    . 

.  Emmetropia,  Emmetropic. 

V.    . 

.  Vision,  Visual  Acuity,  Vertical. 

F.    . 

.  Formula. 

+  ,— 

=   Plus,  Minus,  Equal  to. 

H.    . 

.  Hyperopia,    Hyperopic,     Hori- 

00      . 

.  Infinity,  20  ft.  distance. 

zontal. 

c  . 

.  Combined  with. 

L.  D. 

.  Light  Difference. 

o 

.  Degree. 

L.  E. 

.  Left  Eye. 

nil  III! 

nil  III! 

llllllll 

llllllll 

llllllll 

llllllll 

llllllll 

llllllll 

nil  nil 

nil  nil 

llllllll 

llllllll 

mil 

1 

z 

3 

4 

5 

6 

7 

8 

9 

1 

0  1 

1     1 

a 

11  Mil 

lllllllll 

nil  1 1,1 

IJIUJ 1 

MM 

1  Ijlj  ij 

iiiilii  1 

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II 

nil  nil 

III 

Ui, 

lUilUi 

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ijn  1 

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1  1. 

II  1 

ITTITTTT 

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1  1 

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11 

1 

III  III  III  III 

III  III  III  III 

3 

III  III    II  III 

4 

HI  III  III  III 

5 

III  III  III  III 

Fig.  158. — A.  Centimeters.     B.  Inches. 


469 


470 


APPENDIX. 


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APPENDIX  B. 


ETYMOLOGIES. 

(  Condensed  from  Gould's  Illustrated  Medical  Dictionary,  2d  Ed.) 


Acne  \h.x^1,  a  point]  a  disease  of  the 
sebaceous  glands. 

Amaurosis  \(ifiav()6eLv ,  to  darken]  par- 
tial (or  total)  loss  of  vision. 

Amblyopia  [au^/.iT,  dulled  ;  rj  uipc,  the 
eye]  subnormal  acuteness  of  vision. 

Ametropia  [a  priv. ;  uhpov,  a  measure  ; 
owir,  sight]  the  formation  of  an  im- 
perfect image  on  the  retina,  due  to 
defective  refractive  power  of  the 
media  (or  to  some  abnormality  of 
the  eye). 

Amyloid  [auv/^v,  starch ;  el6o^,  form] 
starch-like. 

Anemia  [d  priv. ;  aiiia,  blood]  (blood- 
less) ;  deficiency  of  blood ;  gener- 
ally understood  as  being  due  to  re- 
lative reduction  in  the  number  of 
red  blood  corpuscles. 

Angioma  [ciyyelov,  a  vessel ;  bua,  a 
tumorj  a  tumor  formed  of  blood- 
vessels. 

Anisokoria  [awcof,  unequal;  Kopij. 
pupilj  inequality  in  the  diameter  of 
the  pupils. 

Anisometropia  [fuzo-oc,  unequal ;  utr- 
pov,  a  measure ;  uib,  the  eye]  a  dif- 
erence  of  refraction  in  the  two  eyes. 

Ankyloblepharon  [ayKv/.ri,  a  loop ; 
^'/.Eoapov,  the  eyelid]  adhesion  of 
the  ciliary  edges  of  the  eyelids. 

Anthrax  \avdpa^,  a  coal  or  carbuncle] 
inflammation  in  the  cellular  tissue, 
due  to  a  specific  bacillus. 

Aphakia  [a  priv.  ;  oaKor,  the  crystal- 
line lens]  the  condition  of  the  eye 
without  the  lens. 

Aplanatic  [a  priv. ;  TiAavaeiv,  to  wan- 
der] rectilinear  lens,  corrected  for 
aberration  of  light  and  color. 

47 


Arcus  senilis  [^arcus,  a  bow  ;  senilis,  of 

the  old]. 
Asthenopia  [d  priv. ;   c6hor,  strength] 

weakness  or  speedy  fatigue  of  visual 

power. 
Astigmatism  [d  priv. ;  ariyfia,  a  point] 

rays  not  brought  to  a  pointer  focus. 
Atrophy  [d  priv. ;  rpoot],  nourishment] 

a  condition  marked  by  wasting  or 

innutrition. 


Blennorrhea  [^T/.ewa,  mucus;  peeiv,  to 
flow]  excessive  mucous  discharge. 

Blepharadenitis  {ji/i^apov,  the  eyelid  ; 
drf//v.  a  gland;  inc,  inflammation] 
inflammation  of  the  Meibomian 
glands. 

Blepharitis  [ji/Ioapov,  the  eyelid  ;  iric, 
inflammation]  inflammation  of  the 
eyelid. 

Blepharophimosis  [ji/I^pov,  the  eye- 
lid; oi ntoaic,  shuiting  up]  abnormal 
smallness  of  the  palpebral  fissure. 

Bothriocephalus  [Sodpiov,  a  pit ;  ne<pa/.Ti, 
head]  a  species  of  tapeworm. 

Bullosa  {bulla,  a  blister]  with  blisters 
or  blebs. 

Buphthalmos  [,3oif,  an  ox ;  o6da7.ii6c, 
eye]  ox-eyed. 


Cancroid  [cancer,  a  crab]  cancer-like, 
semi-malignant. 

Cataract  \_KarapdKrrjc,  a  falling  down  or 
over]  opacity  of  the  lens  or  its  cap- 
sule. 

Catarrh  [jiarappEeiv,  to  flow  down]  in- 
flammation of  a  mucous  membrane. 

Chalazion  [;^a/d^/oi',  a  small  hail- 
stone] a  Meibomian  cyst. 


472 


APPENDIX. 


Chemosis  [x^f^t-xyig,  a  gaping]  a  swell- 
ing (sub-conjunctival). 
Choroid    [x^piov,  skin  ;  el6oc,  like]   the 

vascular  tunic  of  the  eye. 
Chromatic    \_xpu/ia,  color]  relating  to 

color. 
Chromidrosis     [xpij^a,    color ;     W/xif, 

sweat]  colored  sweat. 
Coloboma  [Ko/.oj36eiv,  to  mutilate]  a  fis- 
sure of  parts  of  the  eye,  congenital 

or  traumatic. 
Coma  [K6J//a,  deep  sleep]    abnormally 

deep  or  prolonged  sleep. 
Corectopia  [Kopr/,    the  pupil ;    e/c-oTrof, 

misplaced]     displacement    of    the 

pupil. 
Cornea  [corneus,  horny]  the  anterior 

transparent  segment  of  the  eyeball. 
Cyclitis   [Kt'K/*.of,  a  circle  (around  the 

eye) ;  ing,  inflammation]  inflamma- 
tion of  the  ciliary  body. 
Cysticercus  [Kva-ig,  a  bladder  ;  aepKog, 

a  tail]    scalex    of   the    tapeworm. 

Hydatid. 

D 
Dacryocystitis  [^daKpvov,  a  tear  ;  Kharic, 

a  sac]  inflammation  of  the  lacrimal 

sac. 
Dacryocystoblennorrhea     \6dKpvov,    a 

tear  ;  kvctiq,  a  sac  ;  /JPievm,  mucus  ; 

poia,  a  flow]  flow  of  tears  from  the 

lacrimal  sac. 
Dacryolith    \6aKpvov,  a   tear ;    7Xdog,   a 

stone]  a  lacrimal  calculus. 
Dacryops     \SaKpvov,    a   tear;    uTp,   the 

eye]  watery  eye. 
Daltonism  [Dalton,  an  English  phy- 
sicist] color-blindness. 
Dendritica  [6hdpov,  a  tree]  tree-like. 
Dermoid  [dkpiia,  skin  ;  elSog,  like]  like 

the  skin. 
Dialysis  [dm,  through  ;  Xreiv,  to  loose] 

passing  through. 
Diopter  [did,  through  ;  otpecdai,  to  see] 

the  metric  unit  of  measurement  for 

optical  lenses. 
Distichiasis  [<5<f,  double  ;  arixog,  row] 

double  row  of  eyelashes. 


Ectasia  [en-aaLg,  extension]  abnormal 
distention  or  dilatation  of  a  part. 

Ectropium  [ek,  out ;  Toeneiv,  to  turn] 
eversion  (of  an  eyelid). 


Eczema  [enChiv.  to  boil  over]  a  ca- 
tarrhal inflammatory  disease  of  the 
skin. 

Edema  [ol67//ia,  a  swelling]  swelling, 
due  to  effusion  of  serous  fluid  into 
areolar  tissues. 

Emmetropia  [ii>,  in  ;  fierpov,  measure  ; 
(jix',  eye]  normal  vision. 

Emphysema  [ifKpvaaeiv,  to  inflate]  ab- 
normal collection  of  air  in  the  con- 
nective tissue. 

Encephalocele  [eyKt(l>a?MC,  brain  ;  kc/zIt/, 
tumor]  a  hernia  of  the  brain  through 
a  cranial  fissure. 

Enophthalmos  [iv,  in  ;  bodal/jog,  eye] 
recession  of  eyeball  into  the  orbit. 

Entozoon  [tirdf,  within  ;  (uov,  an  ani- 
mal] an  animal  parasite  within  an- 
other animal. 

Entropium  [ev,  in  ;  rpe-eiv,  to  turn] 
inversion  (of  the  eyelid). 

Epicanthus  [i-/,  on  ;  KavOog,  angle  of 
the  eye]  a  fold  of  skin  passing  from 
nose  to  eyebrow. 

Epiphora   [i-i,  on  ;  (^Epeiv,  to  bear]   a 

persistent  overflow  of  tears. 
Erythropsia  [ipvOpog,  red  ;  bipiq,  vision] 

red  vision. 
Esophoria   [tau  (or  £la(S),  within  ;  <^op- 

eiv,  to   bear]  tending  of  the  visual 

line  inward. 
Exophoria     [e^w,    without ;    (iopeiv,    to 

bear]  tending  of  visual  line  outward. 
Exophthalmos  [f^,  out ;  b<pOalfi6q,  eye] 

abnormal  prominence  of  eyeball. 

F 
Furuncle     \ftirunculus,    Lat.      (from 
Sanskrit),  to  burn]  a  boil. 

G 

Gerontoxicon  [yepwv,  an  old  man ; 
zo^ov,  a  bow].     See  Arcus  senilis. 

Glaucoma  [y^-avKoq,  sea-green]  a  dis- 
ease of  the  eye ;  so-called  on  ac- 
count of  the  green  color. 

Glioma  [}/-/a,  glue ;  hua,  tumor]  a 
variety  of  round-celled  sarcoma. 

H 

Hemeralopia    \j]p.kpa,    day ;    cj,    eye] 

day-vision  or  night-blindness.  (See 

note  under  Nyctalopia^ 
Hemianopsia    \niii,    half;    dv    priv.  ; 

oi^iq,  sight]  blindness  in  one-half  of 

the  visual  field. 


APPENDIX, 


473 


Hemorrhage  [^aifia,  blood  ;  priyvvvai,  to 
burst  forth]  bleeding  from  wounded 
vessels. 

Herpes  zoster  \)p-i]c.  creeping  ;  Cua- 
Ti'ip,  a  girdle]  an  inflammatory  skin 
disease,  characterized  by  vesicles. 

Heterochromia  [e-epoq,  different  ; 
xpuiia,  color]  a  difference  in  color 
(in  the  irides). 

Heteronymous  [ivepor,  different ;  dw^ta, 
name]  of  a  different  name  or  char- 
acter. Crossed.  The  opposite  of 
homonymous. 

Heterophoria  [e-fpoo,  different ;  (popoc, 
tending]  a  tending  of  the  visual 
lines  other  than  to  parallelism. 

Hippus  [iTz-og,  the  horse]  spasmodic 
pupillary  movements,  independent 
of  the  action  of  light.  (Natural  in 
the  horse.) 

Homonymous  [ofj-og,  same ;  ovvfia, 
name]  occurring  on  or  within  the 
same  lateral  half  of  the  body. 

Hordeolum  \Jiardeum ,  barley]  a  stye. 

Horopter  \ppo<;,  boundary  ;  o-TTjp,  an 
observer]  a  line  representing  the 
curve  along  which  both  eyes  can 
join  in  sight. 

Hyaline  [la/.of,  glass]  resembling 
glass. 

Hydrophthalmos  [irfup,  water  ;  6(j>daX- 
fiog,  eye]  increase  in  the  fluid  con- 
tents of  the  eye. 

Hydrops  [i:6puip,  dropsy]  an  abnormal 
collection  of  fluid  in  any  part  of  the 
body. 

Hyperemia  [i'~f/j,  over  ;  aipa,  blood]  a 
congestion  of  blood. 

Hypermetropia  [_i~£p,  over ;  /lerpov, 
measure  ;  wi/',  eye].    See  Hyperopia. 

Hyperopia  \y-vp,  over  ;  ^^^\),  eye] .  That 
condition  of  the  refractive  media  of 
the  eye  in  which,  with  suspended 
accommodation,  the  focus  of  paral- 
lel rays  of  light  is  behind  the  retina  ; 
it  is  due  to  an  abnormally  short  an- 
tero-posterior  diameter  of  the  eye, 
or  to  a  subnormal  refractive  power 
of  its  media. 

Hyperphoria  [i  "sp,  over  ;  oopof,  tend- 
ing] a  tendency  of  a  visual  line  up- 
ward. 

Hyphema  \v-6,  under  ;  aiiia,  blood]  a 
deposit  of  blood  on  the  floor  of  the 
anterior  chamber. 


Hypophoria  \\)t:6,  under ;  ^pog,  tend- 
ing] a  tendency  of  a  visual  line 
downward. 

Hypopyon  \_i~6,  under  ;  ttvov,  pus]  a 
collection  of  pus  in  the  anterior 
chamber. 

Hysteria  [_vaTepa,  the  womb]  a  nervous 
disorder,  once  supposed  to  arise 
from  the  womb. 


Iridectomy  [ipig,  iris  ;  hrop^,  excision] 
cutting  out  part  of  the  iris. 

Irideremia  [Ipig  ;  ip>/fiia,  lack]  absence 

of  one  or  both  irides. 
Iridodialysis  [iptg  ;  SiaXveiv,  to  liberate] 

release  of  ins  at  its  ciliary  border. 

Iridodonesis  [Ipic  ;  Sdvr^aig,  trembling] 
tremulousness  of  the  iris. 

Iridoplegia  [ipig;  '^^ly^,  stroke]  paraly- 
sis of  sphincter  of  the  iris. 

Iridotomy  [ipig ;  rof/^^  a  cutting]  inci- 
sion into  the  iris. 

Iris  [''p<c,  a  colored  halo  or  circle]  the 
anterior  portion  of  the  vascular  tunic 
of  the  eye. 

Iritis  [ipig ;  ctic,  inflammation]  inflam- 
mation of  the  iris. 

Ischemia  [lax^tv,  to  check  ;  aifia, 
blood]  bloodlessness. 

K 

Karyokinesis  [ndprnv,  a  nut  (=  nu- 
cleus) ;  KivTjciq,  change]  changes 
accompanying  maturation  of  the 
ovum. 

Keratitis  [Kepac,  horn  (=  cornea)  ;  i-ig, 
inflammation]  inflammation  of  the 
cornea. 

Keratocele  {liepag,  cornea ;  ktiIt],  tumor] 
a  hernia  of  Descemet's  membrane 
through  the  cornea. 

Keratomalacia  [nkpag,  cornea  ;  pa/.aKca, 
softness]  softening  of  corneal  tissue. 

Keratoscopy  [^Kepag,  cornea ;  (jkotteIv, 
to  observe]  examination  of  the  cor- 
nea. 

Kopiopia  [Ko-og,  straining;  ojf,  eye] 
eye-strain.     Weariness  of  the  eyes. 

Korjectopia  [Koprj,  the  pupil  of  the  eye 
(so-called,  like  the  Latin  pupiV/a,  be- 
cause an  image  appears  in  the  eye) ; 
EKTo-jTog,  misplaced]  displacement  of 
the  pupil. 


474 


APPENDIX, 


Lagophthalmos  [/.aywf ,  hare ;  b<}>0a^n6c, 
eye]  inability  to  close  the  eyes  (from 
the  popular  notion  that  the  hare 
sleeps  with  his  eyes  open). 

Lens  [Lat.,  a  lentil]  a  regularly  shaped 
transparent  object  refracting  lumin- 
ous rays. 

Leukemia  [Aewof,  white  ;  alua,  blood] 
a  condition  of  the  blood,  character- 
ized by  a  relative  increase  in  white 
corpuscles. 

Leukoma  [/.evkuuci,  anything  white]  a 
white  spot  on  the  eye. 

Leukosarcoma  [/.evk6^,  white  ;  oap- 
Kuua,  fleshy  tumor]  non-pigmented 
sarcoma. 

Lithiasis  [?Jdog,  a  stone]  a  callosity 
within  the  eye-lid. 

Lupus  [Lat.,  a  wolf]  a  skin  disease 
due  to  the  tubercle  bacillus. 

Luxatio  [?-6^og,  slanting  (Lat.,  od- 
liquus)^  dislocation. 

M 

Macropsia  \_fianp6Q,  large  ;  b^pig,  sight] 
apparent  mcrease  in  the  size  of  ob- 
jects. 

Malacia  \ua7.aiiia,  softening]  morbid 
softening  of  tissue. 

Marantic  [uapahaiv,  to  make  lean] 
marasmus  ;  general  mal-nutrition. 

Melanosarcoma  \jiDmc,  black ;  aap^, 
flesh ;  bfia,  tumor]  pigmented  sar- 
coma. 

Metamorphopsia  [fieraunpdSeiv,  to 
change  shape ;  6i/'«f,  sight]  appar- 
ent change  in  the  form  of  objects. 

Metamorphosis  [jtieTa/iopcpoEtv]  struc- 
tural change  in  passing  from  the 
embryo  to  the  adult. 

Microphthalmos  [fitKpo^,  small  ;  ocpda?^- 
/xag,  eye]  a  small  (not  pathological) 
eye. 

Micropsia  [uiKpoc,  small ;  oiptg,  sight] 
apparent  decrease  in  the  size  of  ob- 
jects. 

Miosis  [//e/W<f,  a  lessening]  decrease 
in  size  of  the  pupil. 

Mydriasis  [fivSplamg]  abnormal  dilata- 
tion of  the  pupil. 

Myodesopsia  [uvioeidZ/g,  like  a  fly;  oi/Vf, 
vision]  subjective  appearance  of 
muscae  volitantes. 


Myopia  [///f/r,  to  close  ;  wi/',  eye]  near- 
sightedness. Because  near-sighted 
people  partially  close  the  lids. 

Myotomy  [^arg,  muscle  ;  rofi/},  cutting] 
incision  of  a  muscle. 

Myxoma  l/nv^a,  mucus ;  o/xa,  tumor] 
connective-tissue  tumor. 


N 

Nyctalopia  [ti .f,  night ;  (jf,  the  eye] 
night-vision  or  day-blindness. 

Night-vision ;  the  condition  in  which 
the  sight  is  better  by  night  or  in  semi-dark- 
ness than  by  daylight.  It  is  a  symptom 
of  central  scotoma,  the  more  dilated  pupil 
at  night  allowing  a  better  illumination  of 
the  peripheral  portions  of  the  retina.  Dr. 
Greenhill  and  Mr.  Tweedy  have  shown 
that  according  to  the  quite  universal  usage 
of  modem  times,  the  definitions  of  the 
words,  nyctalopia  and  hemeralopia,  have 
been  the  reverse  of  that  of  the  early  Greek 
and  Latin  writers.  The  proper  derivation 
therefore  of  nyctalopia  would  be  from  vv^, 
night,  akaoq,  blind,  dii/),  eye,  the  word 
meaning  night-blindness.  Hemeralopia  was 
likewise  derived  from  ijjiEpa,  day,  h'/iaoq, 
blind,  wi/>,  eye,  and  meant  day-blindness. 
The  attempt  to  reinstate  the  ancient  usage 
can  only  result  in  utter  confusion,  and  the 
words  should  therefore  never  be  used.  See 
Hemeralopia. 

Nystagmus  \vvaTayii6q,  nodding  of  the 
head]  oscillatory  movement  of  the 
eyeballs. 


CEdema.     See  Edema. 

Ophthalmometry  [boOaAfiog,  eye  ;  fjir- 
pof,  measure]  mensuration  of  the 
eyeball,  or  of  the  corneal  curves. 

Ophthalmoplegia  [b^Oa/.fibg ;  tt^.tp/ti, 
stroke]  paralysis  of  the  ocular  mus- 
cles. 

Ophthalmoscope  [_b(p6a?./i6g  ;  OKo-elv,  to 
observe]  instrument  for  examining 
the  interior  of  the  eye. 

Ophthalmotonometer  [u(f>6a?/u6g  ;  rovof, 
tone  ;  fik-pov,  measure]  instrument 
for  measuring  intraocular  tension. 

Optogram    [birrbg,    visible ;  ypd(i>Ecv,  to 

write]  a  faint  image  stamped  on  the 

retina  for  a  brief  period. 
Orthophoria     [_bpd6g,    straight ;     oopoq, 

tending]  tending  of  the  visual  lines 

to  parallelism. 


APPENDIX. 


475 


Pannus  [Lat.,  cloth]  vascularization 
of  the  cornea. 

Panophthalmitis  [-iic,  all  ;  odda/./uoc, 
eye  ;  trie,  inflammation]  inflamma- 
tion of  all  the  tissues  of  the  eye-ball. 

Parallax  [-apd,  beside  ;  aX?,og,  other] 
apparent  displacement  of  an  object. 

Paralysis  [rrapd  ;  /.veiv,  to  loosen]  loss 
of  power  of  motion  in  a  muscle. 

Paresis  [~apd,  from  ;  levai,  to  let  go] 
partial  loss  of  motion  in  a  muscle. 

Periscopic  [-epl,  around ;  (jkotzeIv,  to 
see]  applied  to  lenses  having  a  con- 
cave surface  on  one  side  and  a 
convex  on  the  other. 

Phakomalacia  [oaKog,  lens ;  fia7.aKia, 
softness]  soft  cataract. 

Phimosis  [6iuovv,  to  constrict]  abnor- 
mal smallness  (as  of  the  palpebral 
fissure). 

Phlyctenula  [dim,  of  ^/i/craa'a,  blister] 
a  small  vesicle  or  blister. 

Photometer  [our,  light ;  iihpov,  meas- 
ure] instrument  for  measuring  the 
intensity  of  light. 

Pinguecula  \\-.?Lt.,pingi{is,  fat]  a  small 
tumor  of  the  conjunctiva  bulbi. 

Polioencephalitis  [jrohog,  gray  ;  h/Ke^a- 
7.0V,  bram  ;  ing,  inflammation]  in- 
flammation of  cortical  gray  matter. 

Presbyopia  [rrpEalivQ,  old  ;  ui/;,  eye] 
"  old-sight." 

Pseudo-iso-chromatic  [il>ev6iig,  false  ; 
iaoc,  equal  ;  xp^l^c-,  color]  similarly 
colored  only  to  those  with  color 
amblyobia. 

Pterygium  [T7t'pi.j,  wing]  a  triangular 
patch  of  thickened  conjunctiva. 

Ptosis  [-ruaic,  rriTTreiv,  to  fall]  drooping 
of  the  upper  eyelid. 

Pyorrhea  [-ioi',  pus ;  pnia,  a  flow]  a 
purulent  discharge. 


Rhinorrhaphy  [p/g,  the  nose  ;  pad//,  su- 
ture] reduction  of  the  tissue  of  the 
nose  by  section. 


Sarcoma   [^nap^,  flesh  ;  oita,  tumor]    a 

connective-tissue  tumor. 
Sarcomatosum      [ryap^,      flesh  ;      duo, 

tumor]  of  the  nature  of  sarcoma. 


Scintillans  \jcintillare,  to  sparkle] 
emittmg  sparks. 

Scotoma  [a/coroea',  to  darken]  a  fixed 
spot  in  the  field  of  vision,  corre- 
sponding to  some  abnormality  in  the 
retina  or  optic  centers  in  the  brain. 

Seborrhea  \sebum,  suet  ;  pola,  a  flow] 
an  increase  of  sebaceous  secretion. 

Skiascopy  [o-k/o,  shadow ;  aKo-elv,  to 
observe]  the  shadow-test. 

Staphyloma  [ffra^t;/',^,  grape ;  ofia, 
tumor]  a  grape-like  protuberance 
of  cornea  or  sclera. 

Stenopaic  [ffreroc,  narrow ;  onalng, 
pierced]  a  disk  with  a  narrow  open- 
ing. 

Strabismus  [(T-pa/?/c^«v,  to  squint] 
squint. 

Synchisis  [(Ttj'^iwf ,  a  mixing  together] 
a  confusing  effect. 

Synechia  [triv,  together  ;  sx^iv,  to  hold] 
a  morbid  union  of  parts. 

T 

Tarsorrhaphy  [^rapoSg  ;  paf^,  suture]  an 
operation  upon  the  eyelids. 

Tarsus  Irapaog,  the  tarsus  (a  flat  sur- 
face) ]  the  cartilage  of  the  eyelid. 

Teichopsia  [reZjof,  wall ;  oiiVf,  vision] 
temporary  amblyopia,  with  subjec- 
tive visual  images  like  fortification 
angles. 

Telangiectasis  [Ti?Mc,  end ;  ayyelov, 
vessel ;  sK-aaig,  stretching]  dilata- 
tion of  capillaries. 

Tenotomy  [rtjwv,  tendon  ;  riuveiv,  to 
cut]  tendon  cutting. 

Trachoma  [rpaxyg,  rough]  granular 
conjunctivitis. 

Trichiasis  [Opi^,  a  hair]  abnormal  po- 
sition of  the  eyelashes. 

U 

Uremia  [o'vpnr,  urine  ;  ai/Lta,  blood] 
symptoms  of  blood  poisoning  from 
retained  urinary  excretions. 

Uvea  [Lat.,  a  grape  (from  its  color)] 
the  middle  tunic  of  the  eye. 

X 

Xanthelasma  [^^avffog,  yellow  ;  I7.aa^a, 
a  plate  (lamma)  ]  spots  of  yellowish 
discoloration. 

Xanthoma  \javd6g,  yellow  ;  b^a,  tumor] 
a  yellowish  new  growth  on  the  skin. 

Xerosis  [^T/puaig,  dry]  a  dry  condition. 


NDEX. 


Aberration,  spherical,  343,  380 
Abscess  of  cornea,  230 

of  lid,  145 

of  orbit,  460 
Abscission  of  iris,  258 
Accommodation,  17,  25 

binocular,  79 

decrease  of,  with  age,  45 

measure  of,  41 

paralysis  of,  288 
by  atropin,  270 

range  of,  41 

spasm  of,  289 
Acne,  152 
Acuity,  visual,  33 

determination  of,  34 

differences  in,  34 

of  the  retinal  periphery,  63 
Adaptation,  56 

Adenoid,  of  lacrimal  gland,  169 
Advancement    of   muscle,    operation 
for.  447 

of  Tenon  s  capsule,  447 
Albinism,  283 
Alcoholic  amblyopia,  327 
Amaurosis,  383 

from  alcohol,  327 

from  malarial  fever,  389 

from  quinin,  389 

from  tobacco,  327 

from  uremia,  389 

partialis  fugax,  392 

progressive,  329 
Amaurotic  "  cat's-eye,"  319 
Amblyopia,  383 

color,  385 

diabetic,  389 

ex  anopsia  (from  disuse),  383 

from  cerebral  disease,  390 

intoxication,  327 

tobacco,  327 
Ametropia,  22 

Amyloid,  of  conjunctiva,  219 
Anel's  syringe,  178 
Aneurysm,  arterio-venous,  461 

of  orbit,  467 
Angioma  of  lids,  167 


Angioma  of  orbit,  467 
Angle,  alpha,  83 

gamma,  83 

of  deviation,  90 

of  squint,  83 

of  vision,  34 

refracting  angle  of  prism,  91 
Anisokoria,  269,  284 
Anisometropia,  381 
Ankyloblepharon,  156 
Anterior  capsular  cataract,  225 

nodal  point,  23 

synechia,  230 
Anthrax,  145 
Aphakia,  356 

Apoplexia  subconjunctivalis,  215 
Arcus  senilis,  251 
Arteria  centralis  retinas,   124 

hyaloidea  persistens,  360 
ArtericC  ciliares,  267 
Arterial  pulse,  305 

Artery,  embolism  of  retinal,  311,  312 
Artificial  eye,  422 

pupil  (see  Iridectomy) 
Associated    movements,  disturbances 

of,  437 
Asthenopia — 

accommodative,  363 

muscular,  368,  450 

nervous,  385 
Astigmatism,  47,  376 

irregular,  379 

kinds  of,  50 

measure  of,  51 

physiological,  376 

regular,  47,  376 

with  and  against  the  rule,  377 
Atrophic  excavation  of  disc,  397 
Atrophy,  descending,  330 

optic  nerve,  327 

simple,  329 
Atropin,  270 

conjunctivitis  from,  98 

foUu  les  from,  98 

in  iritis,  275 

in  keratitis,  226 

to  paralyze  accommodation,  41 
Axis  of  eye,  83 


477 


478 


INDEX. 


Axis  of  rotation,  78 

of  vision,  83 
Axis-myopia,  373 


Band  (ribbon)  opacity  of  cornea,  253 
Basedow's  (Graves)  disease,  464 
Beer's  knife,  348 

Beiiman's  artificial  ripening  of  cata- 
ract, 345 
Binocular  lens  of  Aubert,  99 

of  Zehender-  Westien,  99 

vision,  70 
Birth-marks,  167,  467 
Bladder  worm,  408 
Blennorrhea,  188 

neonatorum,  190 

of  conjunctiva,  188 
Blepharadenitis,  149 
Blepharitis,  149 

ciliaris,  149 

hypertrophica,  149 

simple,  149 

squamosa,  150 

ulcerosa,  149 
Blepharophimosis,  156 
Blepharospasm,  158 
Blinding  (dazzling)  of  retina,  320 
Blindness  (see  also   Amblyopia   and 
Amaurosis) 

color,  385 
Blood-vessels  in  the  uveal  tract,  267 
Body,  ciliary,  267 
Bothriocephalus,  411 
Bowman's  membrane,  220 

sounds,  176 
Bruecke's  muscle,  267 
Buphthalmos  congenitus,  400 
Burns  of  conjunctiva,  216 

of  cornea,  251 


Canalis  Cloqueti,  269 

Petiti,  333 

Schlemmii,  269 
Cancer  (see  Carcinoma) 
Canthoplasty,  158 
Canthus  externus  and  internus,  143 
Carcinoma  of  conjunctiva,  219 

of  lid,  165 
Cardinal  points,  22 
Caruncula  lacrimalis,  143 
Cataract  (see  also  Cataracta),  333 

artificial  ripening  of,  345 

capsular,  333 

causes  of,  343 

complete,  333 


Cataract,  extraction  of,  347 
in  the  capsule,  351 
linear,  349 

forms  of,  335 

from  lightning,  343 
naphthalin,  344 
salt,  343 
sugar,  344 

hard, 335 

instruments  for,  347 

lamellar,  342 

soft,  339 

treatment  of,  344.  351 
Cataracta  accreta,  333 

calcaria,  339 

capsularis,  333 

centralis,  341 

posterior,  339 

complicata,  333 

congenitalis,  339 

corticalis,  333 

diabetica,  344 

dura  hypermatura,  338 

gypsea,  339 

hypermatura,  338 

immatura  maturescens,  337 

incipiens,  337 

juvenilis,  339 

lactea,  339 

lenticularis,  333 

matura,  338 

membranacea,  339 

Morgagniana,  338 

nigra,  332 

nuclearis,  333 

polaris  posterior,  341 

pyramidalis,  341 

secondaria,  340,  354 
accreta,  355 

senilis,  335 

stationaria,  341 

traumatica,  339 
Catarrhal  ulcer  of  cornea,  234 
Catarrhus  siccus,  183 
"Cat's-eye,"  319 
Cautery  in  corneal  diseases,  227 
Centering  of  refractive  media,  \\ 
Cerebrocele  (see  Encephalocele) 
Chalazion,  154 

terreum,  156 
Chemosis  conjunctivae,  188 
Chiasm,  optic,  304 
Chloroma,  169 
Choked  disc,  322 
Choroid,  anatomy  of,  267 

coloboma  of,  301 

detachment  of,  300 

diseases  of,  290 

prolapse  of,  300 


INDEX. 


479 


Choroid,  rupture  (laceration)  of,  300 

sarcoma  of,  297 

tuberculosis  of,  296 

warts  of,  301 
Choroidal  ring,  122 
Choroiditis  areolaris,  293 

centralis  circumscripta,  293 

diffusa,  291 

disseminata,  291,  369 

embolica,  296 

exudativa,  290 

metastatica,  296 

septica,  296 

suppurativa,  295 
chronica,  296 
Chororetinitis  centralis,  293 

syphilitica,  294 
Chromidrosis,  148 
Cicatricial  opacity,  253 
Cilia  (see  Lashes) 
Ciliary  body,  267 

diseases  of,  286 

forceps,  150 

injection,  222 

muscle,  267 

paralysis  of,  288 
paresis  of,  288 
spasm  of,  289 

neuralgia,  222 

processes,  267 
Circular  rotation, "]"] 

synechia,  274 
Circulus  arteriosus  iridis  minor,  266 
major,  268 
Circumcision,  242 
Cocain,  270 

in  iritis,  276 

opacity  from,  252 
Coloboma,  artificial,  282 

of  choroid,  301 

of  iris,  283 

of  lid.  165 
Color  amblyopia,  385 

blindness,  385 

sense,  57 

tests  for,  58,  59 
Commotio  retina;,  320 
Cones  of  retina,  301 
Conical  cornea,  260 
Conjugate  deviation,  437 
Conjunctiva,  anatomy  of,  181 

burns  of,  216 

diseases  of,  181 

foreign  bodies  in,  214 

hemorrhage  of,  215 

hyperemia  of,  183 

transplantation  of,  217 

tumors  of,  218 

wounds  of,  215 


Conjunctival  catarrh,  chronic,  183 
Conjunctivitis  blenorrhoica,  188 

catarrhalis,  185 
estiva,  206 

chronica,   183 

crouposa,  193 

diphtheritica,  194 

eczematosa,  207 

follicularis,  196 

gonorrhoica,  190 

granulosa,  199 

lymphatica,  207 

membranacea,  193 

phlyctenulosa,  207 

purulenta,  188 

scrofulosa,  207 

sicca,  183 

simplex,  185 

trachomatosa,  199 

tuberculosa,  206 
Contractures,  secondary,  433 
Conus,  369 

Convergent  squint,  84,  440 
Corectopia,  283 
Cornea,  abscess  of,  230 

anatomy  of,  220 

burns  of,  251 

eczema  of,  231 

facet  of,  224 

fistula  of,  225 

frigeration  of,  251 

inflammations  of,  221 

injuries  of,  247 

leukoma  of,  254 

macula  of,  254 

nubecula  of,  254 

opacities  of,  251 

perforation  of,  225 

phlyctenule  of,  231 

protrusions  of,  257 

puncture  of,  228,  405 

reflection  from  the,  96 

staphylojna  of,  257 

transplantation  of,  256 

tumors  of,  261 

ulcers  of,  222,  234 
Corneal  ellipse,  48,  84 

necrosis,  240 

opacities,  251 

puncture,  405 

ulcer,  234,  235 
"  Corpus  alienum,"  249 
Corpus  ciliare,  267 

vitreum,  360 
Cover  points,  72 
Crab's  eye,  214 
Credes  method,  191 
Creeping   corneal    ulcer    (see    Ulcus 
serpens) 


48o 


INDEX. 


Cyclitis,  286 

plastica,  287 
serosa,  287 
suppurativa,  288 

Cyst  of  conjunctiva,  218 
of  iris,  282 
of  lid  edge,  166 

Cysticercus,  407 

Cystitome,  347 

Cystoid  scars,  406,  407 


Dacryocystitis,  172,  174 
Dacryocystoblennorrhea,  172 
Dacryolith,  172 
Dacryops,  170 
Dacryorrhea,  188 
Daltonism,  385 
Dark  spot,  6g 
Daviel's  incision,  348 

spoon,  348 
Dayblindness  (see  Nyctalopia) 
Dazzling  of  retina,  320 
Decussation  of  optic  nerves,  303 
Deposits    on    Descemet's   membrane, 

247 
Depression  (for  cataract),  346 
Dermoid,  of  conjunctiva,  218 

cyst  of  orbit,  467 
Descemet's  membrane,  221 

deposits  on,  247 
Detachment  of  choroid,  300 

of  retina,  315 
Deviation,  angle  of,  90 

primary,  441 

secondary,  441 
Diabetic  amblyopia,  389 

cataract,  344 
Dieffenbaclis  operation,  165 
Diffusion  theory,  317 
Dilatator  pupillae,  266 
Diopter,  32 

Diphtheria  of  conjunctiva,  194 
Diphtheritic  corneal  ulcer,  235 
Diplopia  (in  squint),  425 
Disc,  optic  (see  Optic  disc) 
Discission,  340,  346 
Dislaceration,  355 
Distichiasis,  153 
Divergence,  facultative,  451 
Divergent  squint,  449 
Double  images  (in  paralysis),  425  et 

seq. 
Douche  for  eye,  185 
Dry  catarrh,  183 
Duboisin,  270 


Echinococcus  cyst  of  orbit,  467 
Ectasia,  264 

ciliaris,  264 

equatorialis,  264 

intercalata,  264 

of  sclera,  263 
Ectopia  lentis,  358 
Ectropium,  163 

cicatricial,  164 

sarcomatosum,  163 
Eczema  from  sublimate,  145 

of  conjunctiva,  207 

of  cornea,  231 

of  lid,  144 

ulcer  from,  232 
Edema  of  lid,  147 
Egyptian  ophthalmia,  199 
Election,  position  of,  451 
Embolism  of  retinal  artery,  311,  312 
Emmetropia,  22 
Emphysema  of  lids,  148,  458 
Encephalocele,  466 
Enophthalmos,  457 

traumaticus,  458 
Entozoa  (see  Parasites),  401 
Entropium,  161 
Enucleation,  421,  422 
Epicanthus,  165 
Epiphora,  170 
Episcleritis,  262 

migrans,  262 
Equilibrium,  test  for  muscular,  92 
Errors  of  refraction,  362 
Erythropsia,  358 
Eserin,  270 

in  glaucoma,  404 
Esophoria,  examination  for,  93 

treatment  of,  453 
Estimation  of   refractive    conditions, 

125 
Evisceration,  467 
Excavation  of  disc,  atrophic,  397 

glaucomatous,  398 
physiological,     124, 

397 
Exclusion  of  image,  75 

regional,  442 
Excursional  field,  82 
Exenteratio  bulbi,  296,  422 

orbiti,  467 
Exophoria,  examination  for,  93 

treatment  of,  453 
Exophthalmia  fungosa,  319 
Exophthalmic  goiter,  464 
Exophthalmometer,  457 
Exophthalmos,  160,  433,  457 

pulsating,  461 


INDEX. 


481 


Exostosis  of  orbit,  466 

Extraction  of  cataract,  347 

Eyeball,  injuries  to,  411 
rupture  of,  414 

Eye  douche,  185 

foreign  bodies  within  the,  415 
movements  of,  76,  425 
muscles,  action  of,  78 


Facultative  divergence,  451 
Fadchen-Keratitis,  238 
False  projection,  71 
Far  point,  30 

Farsightedness  (see  Hyperopia) 
Fatty  tumor  of  conjunctiva,  21 1 
Pick's  tonometer,  138 
Field  of  excursion  (see   Excursional 
field) 
of  vision  (see  Visual  field) 
Filaria,  41 1 
Filtration  angle,  269 

scar,  407 
Fissure,  interpalpebral,  156 
narrowed,  156 
widened,  159 
Fistula  of  cornea,  225 

of  lacrimal  gland,  170 
of  lacrimal  sac,  174 
Flarer's  incision,  162 
"  Flying  specks,"  361 
Fluidity  of  vitreous,  362 
Fluorescin  test,  222 

in  wounds  of  conjunctiva,  216 
of  cornea,  222 
Focal  distance  of  lenses,  32 
illumination,  98 
interval,  50 
line,  48 

point,  anterior,  21 
posterior,  20 
Follicular  catarrh,  196 
Foreign  body  in  conjunctiva,  214 
in  cornea,  249 
in  eyeball,  415 
in  iris,  280 
in  orbit,  458 
Fossa  patellaris,  331 
Fracture  of  orbital  bones,  453 
Frigeration  of  cornea,  251 
Fukala,  extraction  of  lens  in  myopia, 

376 
Function  tests,  17 
Fundus,  normal,  123 

examination  of,  119 
Furuncle,  145 
Fusion,  range  of,  80 

31 


Gaillard's  suture,  162 
Galvanocautery  in  corneal  ulcer,  227 
Gelsemin,  270 
Gerontoxon,  251 
Glands,  lacrimal,  167 
Meibomian,  143 
Mollian,  143 
Glaucoma,  392 

absolutum,  396 
acutum,  395 
evolutum,  395 
fulminans,  396 
hemorrhagicum,  403 
infantile,  400 
inflammatorium,  395 
pathology  of,  401 
primary,  395 
secondary,  400 
simplex,  396 
theories  of,  402 
treatment  of,  403 
varieties  of,  395 
Glioma  retinae,  318 
Goiter,  exophthalmic,  160 
Gonococcus  of  Neisser,  190,  464 
Graefes  and  v.  Graefes  tests,  92 
incision  for  cataract,  349 
symptom,  465 
Granulations  (see  Trachoma) 
Granuloma  of  iris,  279 
Grave's  disease,  464 
Green  cataract  (see  Glaucoma) 
Gumma  of  ciliary  body,  286 
of  iris,  279 


H 

Haab's  magnet  operation,  418 

reflex,  270 
Hartnacks  lenses,  99 
Hemeralopia,  56,  294,  313,  383 
Hemianopsia,  390 

transient,  392 
Hemophthalmos  externus,  146 
Hemorrhage — 

into  anterior  chamber,  280 

into  conjunctiva,  215 

into  lid,  146 
Hernia,  cerebral,  466 
Herpes  febrilis  {Horner),  236 

zoster  cornea;,  235 

ophthalmicus,  143 
Heterochromia,  283 
Heterophoria,  93,  452 
Hippus,  286 
Hirschberg's  magnet  operation,  418 

measurement  of  squint,  90 


482 


INDEX. 


Holmgren' s  color  test,  58 

Homatropin,  270 

Hordeolum,  152 

Horopter,  73 

"  Hutchinson  s  i&eth"  244 

Hyaline  degeneration,  220 

Hyaloid,  220 

Hydrophthalmos  congenitus,  400 

Hydrops  of  lacrimal  sac,  172,  175 

of  optic  nerve-sheath,  323 
Hyoscyamin,  270 
Hyperemia  of  conjunctiva,  183 

of  iris,  271 

of  retina,  306 
Hypermetropia  (see  also  Hyperopia), 

37 
Hyperopia,  363 

absolute,  367 

facultative,  366 

kinds  of,  37 

latent,  40 

manifest,  40 
Hyperphoria,  93,  452 
Hypertrophia  epithelialis  estiva,  206 
Hyphema,  280 
Hypophoria,  93 
Hypopyon  in  cyclitis  suppurativa,  288 

in  iritis  suppurativa,  278 

keratitis,  229 


Identical  retinal  points,  72 
Illumination,  oblique  or  focal,  98 
Images,  retinal,  displacement  of,  71 
Incision  of  David,  348 

of  Flarer,  162 

of  Jacobson,  351 
Infantile  glaucoma,  400 
Injury  to  eye  as  a  whole,  411 

to  orbit,  458 
Insufficiency    of    externi    (see    Eso- 
phoria) 

of  interni,  449 
Intention  trembling,  456 
Intermarginal  portion  of  lid,  142 
Intoxication  amblyopia,  389 
Inverted  image,  106 
Iridectomy — the  operation,  280 

for  glaucoma,  405 

for  optical  purposes,  256 
Irideremia,  283 
Iridocyclitis,  286 

serosa,  277 
Iridocyclochoroiditis,  286,  291 
Iridodialysis,  280 
Iridodonesis,  286,  413 
Iridoplegia,  280,  413 
Iris,  anatomy  of,  265 


Iris,  cysts  of,  282 

hyperemia  of,  27 1 
inflammations  of,  271 
injuries  of,  280 
paralysis  of,  280 
physiology  of,  268 
prolapse  of,  225 
tremulans,  286 
tumors  of,  283 
Iris-shadow  test,  337 
Iritis  gummosa,  279 
nodosa,  279 
papulosa,  275 
plastica,  272 
purulenta,  272 
serosa,  277 
simplex,  272 
suppurativa,  278 
syphilitica,  275,  279 
traumatica,  275 
tuberculosa,  279 


Jacobson' s  incision  for  cataract,  351 
Jequirity,  193,  196 


K 

Keratektasia,  261 
Keratitis  bullosa,  239 

dendritica,  237 

e  lagophthalmo,  239 

eczematosa,  231 

fascicularis,  231 

filamentosa,  238 

from  pressure,  253 

interstitialis  diffusa,  243 

lymphatica,  231 

neuroparalitica,  238 

parenchymatosa,  243 
circumscripta,  246 

phlyctenulosa,  231 

punctata  profunda,  246 
superficialis,  235 

scleroticans,  246 

scrofulosa,  231 

striata,  252 

superficialis  vasculosa,  232 

trachomatosa,  234 

traumatica,  248 

vasculosa  superficialis,  232 
Keratocele,  225 
Keratoconus,  259 
Keratoglobus,  261 
Keratomalacia  infantum,  240 
Keratome,  213,  281 
Keratoplasty,  256,  259 


INDEX. 


483 


Keratoscope  of  Wecker-Masselon,  cyj 
Keratoscopy,  96 
Klebs- Loeffler  bacillus,  195 
Kopiopia  hysterica,  387 


Lupus,  166 
Luxatio  bulbi,  459 

lentis,  359 
Lymph  follicles,  199 


Lacrimal  apparatus,  anatomy  of,  167 

canal,  168 

caruncle,  143 

fistula,  170,  172 

glands,  diseases  of;  i6g 

passage,  diseases  of,  170 

punctum,  168 

sac,  diseases  of,  172 

sound,  176 
Lacrimation  (see  Epiphora) 
Lagophthalmos,  160 
Lamina  cribrosa,  122 

suprachorioidea,  267 
Lashes,  diseases  of,  149 
I^urence's  strabometer,  90 
Lens  (crystaUine),  331 

anatomy  of,  331 

astigmatism  of,  380 

capsule  of,  331 

cataract  of,  333 

changes  of  position  of,  358 

displacement  of,  359 

embryology  of,  332, 

increase  in  size  of,  337 
Lenses,  32 

cylindrical,  52,  378 
Leukoma  adherens,  225 

corneae,  254 
Level,  differences  of,  135 
Lid,  abscess  of,  145 

anatomy  of,  143 

cartilage  of,  143 

coloboma  of,  165 

diseases  of,  143 

eczema  of,  144 

edema  of,  147 

hemorrhage  into,  146 

spasm  of,  157 
Lid  edge,  diseases  of,  149 

forceps  for,  155 
Ligamentum  suspensorium  lentis,  333 
Light  minimum,  53 

sense,  53 

of  the  retinal  periphery,  63 
Lightning,  cataract  from,  343 
Line,  visual  (see  Visual  line) 
Lipoma  of  conjunctiva,  218 
Lithiasis  palpebralis,  156,  184 
Localization  of  opacities,  118 

of  paralyses,  428 
Loss  of  working  power  in  damaged 
eyes,  423-425 


M 

Macropsia,  289 

Macula  corneae,  254 

Maddox  rod,  94 

Magnet  operation  oi  Haab,  418 

oi  Hirschberg,  418 
Magnification     of     ophthalmoscopic 
field  in  inverted  image,  109 
in  upright  image,  107 
Malarial  fever,  blindness  from,  389 
Malingering  (see  Simulation) 
Mariottes  spot,  69 
Massage  in  eczema  of  conjunctiva,  2 10 

in  glaucoma,  404 
Massons  disk,  55 
MeduUated  nerve- fibers,  321 
Meibomian  glands,  143 
Membrana  pupillaris  perseverans,  283, 

284 
Membrane  of  Boivman,  220 

oi  Descemet,i2\  0 

Meniscus  glass,  367 
Meridian  asymmetry,  48 
Meridians,  principal,  47 
Metamorphopsia,  293,  294,  368 
Meter  angle,  79 

lens,  32 
Meyer  s  {H.),  color  test,  59 
Microphthalmos,  455 
Micropsia,  289 
Miotics,  270 

in  glaucoma,  404 
Moll's  glands,  143 
Morgagnts  cataract,  338 

drops,  336 
Morphin,  270 
Motility  of  lens,  359 
Mouches  volantes,  360 
Movements  of  eye,  76 
Mueller  s  horopter,  73 

muscle,  267 
Multiple  sclerosis,  456 

vision,  260 
Muscae  volitantes,  360 
Muscarin,  270 
Muscles,  action  of,  78 
Muscular  asthenopia,  368,  450 

squint,  85  et  seq. 
Musculus  ciliaris,  267 
Mydriatics,  270 
Myelin,  336 
Myodesopsia,  360 
Myopia,  28,  367 


484 


INDEX. 


Myopia,  axis,  373 

forms  of,  29 

measurement  of,  31 

progressive,  371 

school,  373 

stationary,  371 
Myotomy,  434 
Myxoma  of  optic  nerve,  466 
Myxosarcoma,  466 


N 


NageVs  experiment,  432 
Naphthalin  cataract,  344 
Nasal  duct,  stenosis  of,  180 
Near  point,  35 

Nerve,  optic,  diseases  of,  322 
Nervous  asthenopia,  385 
Neurectomia  opticociliaris,  420 
Neuritis  optica,  323,  324 
Neurotomia  opticociliaris,  420 
Nevus  (see  Telangiectasia) 
Nictitatio,  157 
Night-blindness  (see  Hemeralopia) 

shadows  (see  Hemeralopia) 
Neurectomy,  optico-ciliary,  420 
Neuritis  descendens,  325 

intoxication,  327 

myopum,  370 

optica,  324 

retrobulbar,  326 
Neuroglia,  318 
Neuron,  302 

Neurotomy,  optico-ciliary,  420 
Nicotin,  270 
Nodal  point,  23 
Nubecula  corneae,  254 
Nuclear  paralysis,  437 

sclerosis,  344 
Nyctalopia,  326 
Nystagmus,  455 

from  brain  disease,  456 

from  weak  sight,  455 

of  minors,  456 


Oblique  illumination,  98 
Oidema  (see  Edema) 
"Old-sight"  (see  Presbyopia) 
Opacitates  corneae,  251 

corporis  vitrei,  360 
Opacity  in  the  lens,  diagnosis  of,  335 
Opaque  nerve-fibers,  321 
Operation  of  Dieffenbach,  165 

of  Flarer,  162 

of  Pagenstecher,  351 


Operation  of  Saemisch,  228 
Ophthalmometer,  98 
Ophthalmoplegia,  434 

externa,  434 

interna, 434 

totalis,  434 
Ophthalmoscope,  loi 

of  Cocciiis,  1 1 5 

of  Helmholtz,  1 14 

of  Liebreich,  1 1 5 

of  Zehender,  116 

theory  of,  loi 

uses  of,  117 
Ophthalmoscopic  field,  no 

in  inverted  image,  no 
in  upright  image,  112 
Ophthalmotonometer,  138 
Optic  disc,  121 

physiological  excavation   of, 

.124.  397 
nerve,  diseases  of,  322 
anatomy  of,  303 
atrophy  of,  327 
inflammation  of,  324 
neuritis,  324 
radiation,  302,  305 
tracts,  305 

vesicle,  primary,  332 
Optogram,  321 
Optometer,  44 
Orbiculus  ciliaris,  267 
Orbit,  abscess  of,  460 
injuries  to,  458 
sarcoma  of,  467 
tumors  of,  466 
Orthophoria,  92 
Osteoma  of  orbit,  466 
Osteoplasty,  467 


Pagenstecher' s  operation,  351 

salve,  151 
Pannus,  240 

carnosus,  241 

crassus,  241 

eczematosus,  242 

tenuis,  241 

trachomatosus,  242 

traumaticus,  242 
Panophthalmitis,  288,  296 
Papilla  nervi  optici,  122 
Papillary  body,  181 
Papillitis,  324 
Papillo-retinitis,  309,  324 
Parallax,  135 
Paralysis,  nuclear,  437 

of  accommodation,  288 


INDEX. 


485 


Paralysis  of  ciliary  muscle,  288 

of  eye  muscles,  425 
Parasites,  407 
Paresis,  288,  426 
Pars  ciliaris  retinae,  267 
Pemphigus,  219 
Pericorneal  injection,  222,  272 
Perimeter,  66 
Periostitis  orbitje,  459 
Peripheral  linear  extraction,  349 
Petit,  canal  of,  333 
Pfluegers  color  tests,  59 
Phacomalacia,  339 
Phlegmon,  146 
Phlyctena  pallida,  206 
Phlyctenula  of  conjunctiva,  207 

of  cornea,  231 

pallida,  206 
Photometer,  54 
Photophobia  in  iritis,  272 

in  keratitis,  234 
Phthisis  bulbi,  226 
Physiological  excavation,  124,  397 
Pigment  degeneration,  313 

epithelium,  266 
Pilocarpin,  270 
Pinguecula,  211 
Point,  far,  30 

near,  35 

nodal,  23 

principal,  22 
Polyopia  (see   also   Multiple  vision), 
260 

monocularis,  335 
Polypi  of  conjunctiva,  218 
"  Pop-eye,"  457 
"  Position  of  election,"  451 
Posterior  synechia,  230,  273,  287, 405 
Presbyopia,  46 
Pressure  bandage,  227 

effect  on  cornea,  253 
Primary  deviation,  441 

glaucoma,  395 
Principal  meridians,  47 

planes,  22 

points,  22 
Prisms,  91 

refracting  angle  of,  91 

uses  of,  93,  450,  453 
Probe,  lacrimal,  176 
Processus  ciliaris,  267 
Progressive  amaurosis,  329 
Projection  of  images,  75 
Prolapse  of  iris,  225 

of  vitreous,  350 
Protrusions  of  the  cornea,  257 
Pseudo-erysipelas,  146 
Pseudo-glioma,  320 
Pseudo-isochromatic  cards,  58 


Pterygium,  211 

advancing,  212 

stationary,  212 
Ptosis,  157 

Pulsating  exophthalmos,  461 
Punctum  lachrymale,  168 

proximum,  35,  41 

remotum,  30 
Puncture  of  cornea,  228,  405 
Pupil,  265 

changes  in,  284 

closure  of,  472 

contraction  of,  266 

dilatation  of,  266 

influence  of  size  of,  upon  ophthal- 
moscopic field,  1 10 
Purkmje- Sanson' s\m?t.gts,  26,  100,  356 
Pyoktanin,  227 
Pyorrhea,  188 


Quinin,  blindness  from,  389 


Range  of  accommodation,  41 

of  fusion,  80 
Rays  of  construction,  21 

of  direction,  23 
Reclination  (for  cataract),  346 
Red  blindness,  57 

vision  after  cataract,  358 
Reflex  from  vessels,  124 

in  fundus,  125 

nuclear,  100 

of  Haab,  270 
Refraction,  17 

errors  of,  362 

of  lenses,  356 

of  prisms,  91 

ophthalmoscope,  116 
Reicherfs  membrane,  220 
Relation  between  accommodation  and 

convergence,  81 
Relative    range    of   accommodation, 
80 

of  fusion,  82 
Retina,  anatomy  of,  301 

detachment  of,  315 

diseases  of,  306 

glioma  of,  318 

hemorrhage  from,  307 

hyperemia  of,  306 

inflammations  of,  308 

injuries  of,  320 

physiology  of,  301 


486 


INDEX. 


Retina,  vessels  of,  304 
Retinitis  albuminurica,  308 
diabetica,  310 
hemorrhagica,  308 
leukemica,  310 
pigmentosa,  313 
syphilitica,  311 
Retrobulbar  neuritis,  326 
Ribbon-like  opacities,  253 
Rod  optometer,  43 
Rods  and  cones,  302 
Rupture  of  eyeball,  414 


SaemiscJis  operation,  228 
Sarcoma  of  conjunctiva,  218 

of  choroid,  297 

of  iris,  283 

of  orbit,  467 
"  Scanning  speech,"  456 
Schemer's  experiment,  24 
Schmidt- Rimpler  s  refractometer,  130 
School  myopia,  373 
Sclera,  anatomy  of,  221 

diseases  of,  262 

protrusions  of,  263 

tumors  of,  265 

wounds  of,  265 
Scleral  border,  221 

ring,  122 
Sclerectasia  anterior,  262 

posterior,  290,  369 
Scleritis,  262 
Sclerochoroiditis  anterior,  262,  290 

posterior,  290,  369 
Sclerotomy,  406 

Sclerosis  of  the  lens  nucleus,  344 
Scopalamin,  270 
Scotoma,  physiological,  69 

circumscribed,  294 
Seborrhea,  149 

fluida,  149 

sicca,  149 
Secondary  contractures,  433 

deviation,  441 

glaucoma,  400 
Seebeck's  {Holmgren  s)  color  tests,  58 
Senile  ectropion,  164 

macular  changes,  321 
Sense  of  color  (see  Color  sense) 
Sense  of  distance,  71 
Septic  embolism,  312 
Serpiginous  ulcer,  229 
Shadow  of  iris  in  diagnosticating  cat- 
aract, 337 
Shadow  test  (see  Skiascopy) 
Shortsightedness  (see  Myopia) 


Silver,  nitrate  of,  in  conjunctivitis,  191, 

192 
Simulation,  387 
Sinus  cavernosus,  462 

thrombosis,  464 
Skiascopy,  131 
Snellen's  suture,  164 
Snow  blindness,  384 
Soft  cataract,  339 
Sounds,  lacrimal,  176 
Spasm  of  ciliary  muscle,  289 
Spherical  aberration,  343,  380 
Sphincter  pupillae,  266 
Spring  catarrh,  207 
Spud  for  removing  foreign  bodies,  250 
Squint  (see  also  Strabismus),  70,  83 

angle  of,  83 

convergent,  440 

downward,  85 

inward,  84 

latent,  449 

manifest,  84 

muscular,  85  ei  seq. 

outward,  84 

paralytic,  425 

upward,  85 
Staphyloma,  264 

corneae,  257 

posticum,  264,  290,  369 

sclerse,  264 
Stauungspapille,  322 
Stellwags  symptom,  464 
Stenopaic  glasses,  380 

slit,  51 
Stereoscope,  448 
Stiff  neck,  427 
Strabismus  (see  also  Squint),  83 

alternans,  441 

concomitans,  89,  440 

deorsum  vergens,  85 

divergens,  449 

paralyticus,  85,  425 

periodicus,  440 

sursum  vergens,  85 

unilateralis,  441 

vision  in,  440 
Strabometer,  90 

Stricture  of  lacrimal  passages,  172 
Stricturotomy,  177 
Sty,  152 

Sublimate  eczema,  145 
Suction  (for  cataract),  346 
Suppression  of  retinal  images,  75 
Suspensory  ligament,  333 
Suture,  Gaillard's,  162 

Snellen's,  164 
Symblepharon,  217 
Sympathetic  ophthalmia,  418 
Synchysis,  362 


INDEX. 


487 


Synchysis  scintillans,  362 
Synechia  anterior,  230 

posterior,  230,  273,  287 

totalis,  274 


Taenia  solium,  407 
Tapetum  cellulosum,  319 
Tarsitis,  156 
Tarsorrhaphy,  160 
Tarsus,  diseases  of,  154 
Tatooing,  255 
Tear  (see  Lacrimal) 
Teichopsia,  392 
Telangiectasia,  167,  467 
Tenon's  capsule,  447 

advancement  of,  447 
Tenotomy  for  heterophoria,  454 

for  paralysis,  440 

for  strabismus,  445,  452 
Tension  in  glaucoma,  392 

measurement  of,  137 
Tensor  choroideae,  267 
Test  frame,  379 

lenses,  32 
Thread-worms,  411 
Thrombosis,  marasmatic,  464 

of  vena  centralis  retinae,  313 

of  vena  ophthalmica,  464 

septic,  464 
Tobacco  amblyopia,  327 
Tonometer,  139 
Torpor  retinas,  316 
Torticollis,  427 
Total  posterior  synechia,  274 
Trachoma,  199 

corneal  ulcer  in, 234 

follicles  in,  200 
Transillumination,  118 
Transplantation  of  ciliary  floor,  163 

of  conjunctiva,  217 

of  cornea,  256 
Traumatic  cataract,  339 

keratitis,  248 

pannus,  242 
Trichiasis,  149,  153 
Tuberculosis  of  choroid,  296 

of  conjunctiva,  206 

of  iris,  279 

of  lid,  166 
Tumors  of  conjunctiva,  218 

of  cornea,  261 

of  iris,  283 

of  lid,  165 

of  orbit,  466 

of  retina,  318 

of  sclera,  265 
Tunica  media,  265 

uvea,  265 


U 

Ulcer  of  cornea,  222 

of  lid-edge,  152 
Ulcus  corneae,  222 

rodens,  230 

serpens,  229 
Upright  image  (direct  method),  104 
Uremic  amaurosis,  389 

retinitis,  308 
Uvea,  265 
Uveal  tunic,  265 


Vaccination  pustule,  152 

Vascular  network  around  cornea,  221 

Vena  centralis  retinae,  124 

Venae  ciliares,  268 

vorticosae,  268 
Venous  pulse,  305 
Verrucae  (see  Warts) 
Vertigo  in  squint,  425 
Vision,  acuteness  of,  17,  33 

binocular,  70 

indirect,  61 

monocular,  365 

multiple,  260 

principles  of,  17 
Visual  angle,  34 

acuity,  33 

field,  65,  304 

color  limits  in,  69 

line,  83 
Visus  reticulatus,  295 
Vitreous,  abscess  of  (see  Panophthal- 
mitis) 

anatomy  of,  360 

central  canal  of,  269,  360 

fluidity  of,  362 

opacities  in,  360 

prolapse   of   (in   cataract   opera- 
tion), 350 
Vorticose  veins,  268 


W 

Warts  of  choroid,  301 

of  lid,  166 
Weaksightedness,  cerebral,  390 
Weber  s  lacrimal  sound,  176 

5coop,  349 
Wolfberg  s  test  for  color  sense,  60 
Wool  test  for  color  sense,  58 
Worms  (see  Parasites) 
Wounds  of  choroid,  300 

of  conjunctiva,  215 

of  cornea,  247 


488  INDEX. 

Wounds  of  eyeball,  411  Xerosis  of  conjunctiva,  213 
of  orbit,  458  parenchymatosa,  195,  202 

X  Y 

Xanthelasma,  167  Yellow  ointment,  151 

Xanthoma,  167 

Xerosis  bacilli,  213  _ 

epithelialis,  213 

marantica,  240  Zonula  of  Zinn,  333 


CATALOGUE 
No.  1. 


REAP  "SPECIAL  NOTE"   BELOW. 

JUNE,  1896. 


CATALOGUE 


Medical,  Dental, 

Pharmaceutical,  and  Scientific  Publications, 

WITH    A    SUBJECT    INDEX, 

OF  ALL  BOOKS  PUBLISHED  BY 

P.  BLAKISTON,  SON  &  CO. 

(Successors  to  Lindsay  &  Blakiston), 

PUBLISHERS,    IMPORTERS,    AND     BOOKSELLERS, 

IOI2  WALNUT  ST.,  PHILADELPHIA. 


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CATALOGUE  No.   2. — Medical  Books.     Illustrated  with  portraits  of  prominent  authors 

and  figures  from  special  books. 
CATALOGUE  No.  3. — Pharmaceutical  Books. 
CATALOGUE  No.  4. — Books  on  Chemistry  and  Technology. 
CATALOGUE  No.   5. — Books  for  Nurses  and  Lay  Readers. 
CATALOGUE  No.  6. — Books  on  Dentistry  and  Books  used  by  Dental  Students. 
CATALOGUE  No.  7. — Books  on  Hy^^iene  and  Sanitary  Science ;  Including  Water  and 

Milk  Analysis,  Microscopy,  Physical  Education,  Hospitals,  etc. 
SPECIAL  CIRCULARS.— Morris'  Anatomy;  Gould's  Medical  Dictionaries;  Moullin's 

Surgery;  Books  on  the  Eye;  The  ? Quiz  Compends?  Series, 

Visiting  Lists,  etc.     We  can  also  furnish  sample  pages  of 

many  of  our  publications. 


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CLASSIFIED  LIST,  WITH  PRICES, 

OF  ALL  BOOKS  PUBLISHED  BY 

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ANATOMY. 
Ballou.     Veterinary  Anat.      ^.80 
Campbell.     Dissecior.         -     i.oo 
Heath.    Practical,     jth  Ed.      4.25 
Holden.  Dissector.  Oil-cloth,  2.50 

Osteology.    -        -  5.25 

Landmarks.     4th  Ed.    i.oo 

Macalister's  Text-Book.     -    5.00 
Marshall's    Phys.  and  Anat. 

Diagrams.  (40.00  and    60.00 

Morris.  Text  Book  of.  791  lUus. 

Clo  ,  6.00;  Sh.,  7.00;  J4  Rus.,  8.00 
Potter.       Compcnd  of.       5th 

Ed.     133  Illustrations.  -  .80 

Wilson's  Anatomy.  izthEd.  5.00 

ANESTHETICS. 
Buxton.     Anzsthetics.   •  1.25 

Turnbull.    3d  Ed.  -         3.00 

BRAIN  AND  INSANITY. 
Blackburn.  Autopsies.  -  1.25 
Govt^ers.  Diagnosis  of  Dis- 
eases of  the  Brain.  2d  Ed.  1.50 
Horsley.  Brain  and  S.  Cord.  2.50 
Hyslop.  Mental  Physiology.  4.25 
Lewis   (Bevan).     Mental 

Diseases.     2d  Ed.  -  

Mann's  Psychological  Med.     3.00 
Regis.     Mental  Medicine.    -    2.00 
Stearns.    Mental  Dis.    Illus.    2.75   j 
Tuke.     Dictionary  of  Psycho- 
logical Medicine.     2  Vols.     10.00 
Wood.     Brain  and  Overwork.     .40 

CHEMISTRY. 
See  Technological  Books,  Water. 
Allen.     Commercial    Organic 
Analysis.  2d  Ed.  Volume  I.  

Volume  II.  -        -         

Volume  III.     PartL    

Volume  III.     Part  II.  4.50 

Volume  III.  Part  III. 

— —  Diabetic  Urine.         -       2.25 
Bartley.     Medical  and  Phar- 
maceutical.    4th  Ed.       -        2.75 

Bloxam's  Text-Book.  8th  Ed.  4.25 
Caldwell.      Qualitative    and 

Quantitative  Analysis.        -     1.50 
Clowes     Qiial.  Analysis.       -     i.oo 
Groves  and  Thorp.     Chemi- 
cal Technology    Vol.  I.  Fuels  5.00 
Vol.  II.     Lighting.      -     4.00 
Holland.    Urine,  Gastric  Con- 
tents, Poisons  and  Milk  Anal- 
ysis. 5th  Ed.         ...     I.oo 
LefTmann's  Compend.         •      .80 
— —    Progressive  Exercises,  i.oo 

Milk  Analysis.    -       -     1.25 

Muter.     Pract.  and  Anal.         1.25 
Richter's  Inorganic.   4th  Ed.   1.75 

Organic.     2d  Ed.  4.50    \ 

Smith.      Electro-Chem.  Anal.  1.25    j 
Smith  and  Keller.     Experi-  I 

ments.     3d  Ed.     Illus.  .60   j 

Stammer.     Chem.  Problems.    .50 
Sutton.     Volumetric  Anal.        4.50   { 
Symonds.     Manual  of. 
Trimble.     Analytical. 
Watts.     (Fowne's)  Inorg. 

(Fowne's)  Organ. 

Woody.  Essentials  of.  4th  Ed. 

CHILDREN. 
Brothers.     Infant  Mortality.  1.50 
Hale.     Care  of  -  .50 

Hatfield.     Compend  of.  .80 

Meigs.      Infant    Feeding    and 

Milk  Analysis.  -  .50 

Money.     Treatment  of.    -         2.50 
Muskett.     Treatment  of.  1.25 

Po\vcr.    Surgical  Diseases  of.  2.50 
Starr.    Digestive  Organs  of.       2.00 

Hygiene  of  the  Nursery,  i.co 

Taylor  and  Wells.  Manual. 


CLINICAL  CHARTS. 
Griffiths.     Graphic.    Pads.     $0.50 
Temperature  Charts.    "  .50 

COM  PEN  DS 
And  The  Quiz-Contpends. 

Ballou.     Veterinary  Anat.  .80 

Brubaker's  Physiol.  7th  Ed.  .80 

Fox  and  Gould.     The  Eye.  .80 

Hall.     Pathology.     Illus.  .80 

Nose  and  Ear.           -  .80 

Hatfield.     Children.          -  .80 

HorAvitz.    Surgery.     5th  Ed.  .80 

Hughes.  Practice.  2  Pts.  Ea.  .80 

Landis.    Obstetrics.    5th  Ed.  .80 

Leffmann's  Chemistry.  4ih  Ed.  .80 

Mason.     Electricity.        -  .75 

Potter's    Anatomy,   5th  Ed.  .80 

Materia  Medica.  6th  Ed.  .80 

Stewart,  Pharmacy.  5th  Ed.  .80 

Warren.     Dentistry.    2d  Ed.  .80 

Wells.     Gynaecology.      -  .80 

DEFORMITIES. 
Reeves.      Bodily   Deformities 
and  their  Treatment.     Illus.   1.75 

DENTISTRY. 
Barrett.     Dental  Surg.   -  i.oo 

Blodgett.  Dental  Pathology.  1.25 
Plage.     Plastic  Filling.  -  4.00 

FilleDro^vn.  Op.  Dent.  Illus.  2.25 
Gorgas.  Dental  Medicine.  4.00 
Harris.     Principles  and  Prac.  6.00 

Dictionary  of.     5th  Ed.  4.50 

Heath.     Dis.  of^  Jaws.        -     4.50 

Lectures  on  Jaws.  Bds.    .50 

Richardson.  Mech.  Dent.  4.00 
Sewell.  Dental  Surg.  -  z.oo 
Taft.    Operative  Dentistry.      3.00 

,  Index  of  Dental  Lit.       2.00 

Talbot.  Irregularity  of  Teeth.  3.00 
Tomes.     Dental  Surgery. 
Dental  Anatomy. 


Harlan.     Eyesight.  -  .40 

Hartridge.  Refraction.  sthExl.  i.oo 

Ophthalmoscope.    -         1.25 

Hansen   and    Bell.    Clinical 

Ophihalmology.  120  Illus.  1.50 
Macnamara.  Diseases  of.  3.50 
Meyer.  Text-Book.  -  3.50 
Morton.  Refraction.  4th  Ed.  i.oo 
Ohlemann  and  Oliver.  Ocu- 
lar 1  herapeutics.     -        -        

Phillips.   Spectacles  and  Eye- 
glasses.    49  Illus.     2d  Ed.      I.oo 
Swanzy's  Handbook.  4th  Ed.  2.50 
Walker.     Student's  Aid.  1.50 

FEVERS. 
Collie,  On  Fevers.    -  2x0 

■Washbourn  and  Goodall.    

HEADACHES. 
Day.    Their  Treatment,  etc.     i.oo 
HEALTH  AND  DOMESTIC 
MEDICINE. 
Bulkley.    The  Skin.        -  .40 

Burnett.     Hearing.         -  .40 

Cohen.  Throat  and  Voice.  .40 
Dulles.  Emergencies.  4th  Ed.  i.oo 
■40 
•40 
.40 
•40 


4.00 

3-50 

80 


Harlan.     Eyesight. 
Hartshorne.    Our  Homes. 
Osgood.     Dangers  of  Winter. 
Packard.     Sea  Air,  etc. 
Richardson's  Long  Life. 
Westland.     The  Wife  and 

Mother.         ... 
■White.    Mouth  and  Teeth. 
Wilson.     Summer  and  its  Dis. 
■Wood. 


Warren's  Compend  of. 

Dental    Prostheses   and 

Metallurgy.     Illus.         -  1.25   i 

White.    Mouth  and  Teeth.         .40  ' 

DICTIONARIES. 
Cleveland's  Pocket  Medical.     .50 
Gould's  Illustrated  Dictionary 
of  Medicine,  Biology,  and  Al- 
lied Sciences,  etc.     Leather, 
Net,   $10.00;     Half    Russia, 
Thumb  Index,        -        Net,  12  00 
Gould's  Medical  Student's  Dic- 
tionary. J^  Lea.,  2.75;  J4  Mor. 
Thumb  Index.     -        .        -     3.50 
Gould's    Pocket    Dictionary. 
12,000  medical  words.    Lea., 
100:  Thumb  Index,        -         1.25 
Harris'  Dental.  Clo. 4.50;  Shp.5.50 
Longley's  Pronouncing.  .75 

Maxwell.  Terminologia  Med- 
ica Polyglotta.  -        -        3.00 
Treves.    German-English.        3.25 

EAR. 
Burnett.     Hearing,  etc.  .40 

Dalby.    Diseases  of.   4th  Ed.  2.50 
Hall.     Compend.         -      -  .80 

Hovell.     Treatise  on.  •     5  00 

Pritchard.     Diseases  oL  1.25 

ELECTRICITY. 
Bigelow.  Plain  Talks  on  Medi- 
cal Electricity.     43  Illus.  i.oo 
Mason's    Electricity   and    its 

Medical  and  Surgical  Uses.       .75 
Jones.      Medical    Electricity. 
2d  Ed.     Illus.  -        -        2.50 

EYE. 
Arlt.     Diseases  of.   -        -  1.25 

Fick.     Handbook  of  Dis.  

Fox  and  Gould.    Compend.  $0  80 
Go>wer's  Ophthalmoscopy.       4.00 


1.50 
.40 
•45 


Overwork. 
HEART. 
Sansom.     Diseases  of.       -        6.co 

HYGIENE. 
Canfield.  Hygiene  of  the  Sick- 

Room.      ....         1.25 
Coplin  and  Bevan.    Practi- 
cal Hygiene.     Illus.        -         3.^5 
Fox.     Water,  Air,  Food.  3.50 

Kenwood.       Public     Health 

Laboratory  Guide.  -  2.00 

Lincoln.    School  Hygiene.         .40 
McNeill.     Epidemics  and  Iso- 
lation Hospitals.      •        -        3.50 
Notter  and  Firth.  -        7.00 

Parkes'  (E.j.    See  "  Notter." 

(L.  C.),  Manual.  2.50 

Elements  of  Health.        1.25 

Starr.  H  vgiene  of  the  Nursery,  i.oo 
Stevenson  and  Murphy.  A 

Treatise  on   Hygiene.     In  3 

Vols.     Circular        Vol.  I,     6.00 

vpon  application.     Vol.  11,    6.00 

Vol.  Ill,   5.00 

Wilson's  Handbook.   7th  Ed.  3.C0 

Weyl.    Coal-Tar  Colors,  1.25 

JOURNALS,  Etc. 
Ophthalmic  Review.   12  Nos.  3.00 
New  Sydenham   Society's 

Publications,  each  year.     -    8.00 

KIDNEY  DISEASES. 

Ralfe.     Dis.  of  Kidney,  etc.  2.00 

Thornton.    Surg,  of  Kidney.  1.50 
Tyson.     Bright's   Disease 

and  Diabetes,  Illus.          -  2.50 

M  ASSAGE. 

Kleen  and  Hart^vell.      -  2.25 

Murrell.     Massage.  5th  Ed.  1.25 

Ostrom.   Massage.  87  Illus.  i.oo 

MATERIA  MEDICA. 
Biddle.    13th  Ed.    Cloth,  4.00 

Bracken.     Materia  Med.  2.75 

Davis.     Essentials  of  Materia 

Med  and  Pres.  Writing  of.  1.50 
Gorgas.  Dental.  5th  Ed.  4.fo 
Potter's  Compend  of.  sth  Ed.      .80 


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CLASSIFIED  LIST  OF  P.  BLAKISTON,  SON  <^  CO:S  PUBLICATIONS. 


Potter's  Handbook  of.    Fifth  I 

Ed.    Cloth,  4.00  :  Sheep,        $5.00 

Sayre.   Organic  Materia  Med.  | 

and  Pharmacognosy.       -         4.00  1 

White  &  Wilcox.  Mat.  Med.,  ! 

Pharmacy,       Pharmacology,  I 

and    Therapeutics.     3d  Ed.  1 

Enlarged.    Cloth,  2.75 ;  Sh.    3.25 

MEDICAL  JURISPRUDENCE. 

Mann,     Forensic  Med.        -      6.50 

Reese.  Medical  Jurisprudence 
&Toxicology  ,4lh  Ed  3.00;  Sh.  3.50 
MICROSCOPE. 

Beale.     How  to  Work  with.     6.50 

In  Medicine.         -  6.50 

Carpenter.     The  Microscope. 

7th  Ed.     800  Ulus.  -        5.50 

Lee.  Vade  Mecum  of.  -  4.00 
MacDonald.     Examination  of 

Water  and  Air  by.  -  2.50 

Reeves.  Medical  Microscopy. 

llUistrated.       -        -        -         2.50 
^Vethered.     Medical  Micros- 
copy.    Illus.        .        -        .     2.00 
MISCELLANEOUS. 
Black.     Micro-organisms.  .75 

Burnet.  Food  and  Dietaries.  1.50 
Davis.  Text-book  of  Biology.  3.00 
Duckworth.  On  Gout.  -  6.00 
Garrod.  Rheumatism,  etc.  5.00 
Gould.  Borderland  Studies.  2.00 
Gowers.  Dynamics  of  Life.  .75 
Haig.     Uric  Acid.  -        -    3.C0 

Hare.  Mediastinal  Disease.  2.00 
Harris  and  Beale.  Consump- 
tion. .  -  .  .  2.50 
Henry.  Anaemia.  -  -  .50 
Leffmann.  CoalTar Products.  1.25 
Powell.  Lungs,  etc.  -  -  4  00 
Treves.     Physical  Education.    .75 

NERVOUS  DISEASES,  Etc. 
Gowers.    Manual  of.    2d  Ed. 

530  Illus.  Vol.  1,3  00;  Vol.  2, 4.00 
Syphilis  and  the  Nerv- 
ous System.        -        -        .      1.00 

Diseases  of  Brain.  1.50 

Clinical  Lectures.  2.00 

Epilepsy.     New  Ed.      

Horsley.      Brain  and    Spinal 

Cord.  Illus.  -  -  -  2.50 
Obersteiner.   Central  Nervous 

System.  -  -  .  -  5.50 
Ormerod.  Manual  of.  -  i.oo 
Osier.     Cerebral  Palsies.  2.00 

Chorea  -  -         2.00 

Page.     Injuries  of  Spine.  

Railway  Injuries.       -      2.25 

Thorburn.      Surgery    of    the 

Spinal  Cord.  -  -  .  4.00 
Watson.     Concussions.  i.oo" 

NURSING. 
Canfield.  Hygiene  of  the  Sick- 

Room.  ...  -  1.25 
Cullingworth.    Manual  of.        .75 

Monthly   Nursing.  .40 

Domville's  Manual.  7th  Ed.  .75 
Fullerton.     Obst.  Nursing,      i.oo 

Nursing   in   Abdominal  1 

Surg,  and  Dis.  of  Women,  1.50  ' 

Humphrey.  Manual.  ijthEd.  i.co  i 
Shawe.     District  Nursing.        i.oo 
Starr.  Hygiene  of  the  Nursery.  I.oo 
Temperature  Charts.    -  .50  | 

Voswinkel.     Surg    Nursing,    i.oo 

OBSTETRICS.  ' 

Bar.     Antiseptic  Midwifery,     i.oo 
Cazeauxand  Tarnier.   Text- 
Book  of.     Colored  Plates.        4.50 
Davis.     Obstetrics.     Illus.       a.oo  | 
Landis.    Compend    sh  Ed.      .80  j 
Schultze.  Obstetric  Diagrams. 

20  Plates,  map  size.        Net,  26.00 
Strahan.    Extra-Uterine  Preg.    .75  ! 
Winckel's  Text-book.  5.00 

PATHOLOGY  &  HISTOLOGY.   1 
Blackburn.     Autopsies.  1.25   ^ 

Blodgett.  Dental  Pathology     1.25  1 
Gilliam.     Essentials  of.     -  .75 

Hall     Compend.     Illus.       -       .80  ' 
Stirling.    Histology.    2d  Ed.  2.00  I 


Stohr's  Histology.  -         

Virchow.     Post-mortems.       ^.75 

PHARMACY 
Beasley's  Receipt-Book.      -    2.00 
— —  Formulary.      -        -  2.00 

Coblentz.  Manual  of  Pharm.  3.50 
Proctor.  Practical  Pharm.  3.00 
Robinson.  Latin  Grammar  of.  1.75 
Sayre.    Organic  Materia  Med. 

and  Pharmacognosy.  -  4.00 
Scoville.     Compounding.  2.50 

Stewart's  Compend.  5th  Ed.  .80 
U.   S.    Pharmacopoeia.     7th 

Revision.  Cl.  2.50;  Sh.,  3.00 

Select  Tables  from  U.  S.  P.       .2$ 

■White  and 'Wilcox.  Materia 

Medica  and  Phar.     3d  Ed.      2.75 

PHYSICAL  DIAGNOSIS. 

Tyson's  Manual.  2d  Ed.  Illus.  1.25 

PHYSIOLOGY. 
Brubaker's  Compend.     Illus- 
trated.    7th  Ed.       -       -          .80 
Kirkes*  New  13th  Ed.     (Au- 
thor's Ed.)  Cloth,  3.25;  Sh.,  4.00 
Landois'  Text-book.  845  Illus- 
trations.        -        -  -        

Starling.  Elements  of.  -  i.oo 
Stirling.  Practical  Phys.  2.00 
Tyson's  Cell  Doctrine.  -  1.50 
Veo's  Manual.  254  Illustrations 
6th  Ed.  Cloth,  2.50  Sheep,  3.00 
POISONS. 
Murrell.  Poisoning.  -  i.co 
Reese.  Toxicology.  4th  Ed.  3.00 
Tanner.     Memoranda  of.  .75 

PRACTICE. 
Beale.    Slight  Ailments.  1.25 

Charteris,  Guide  to.        -  2.00 

Fowler's  Dictionary  of.  -  3.00 
Hughes.  Compend.  2  Pts.  ea.   .80 

Physicians'  Edition. 

I  Vol.  Morocco,  Gilt  edge.  2.25 
Roberts.  Text-book.  9th  Ed.  4.50 
Taylor's  Manual  of.     -  2.00 

Tyson.    The  Practice  of  Med.  5.50 

PRESCRIPTION  BOOKS. 
Beasley's  3000  Prescriptions.   2.00 

Receipt  Book.        -  2.00 

Davis.     Materia  Medica  and 

Prescription  Writing.  -  1.50 
Pereira's  Pocket-book.  .75 

■Wythe's  Dose  and  Symptom 

Book.     17th  Ed.     -        -  .75 

SKIN. 
Anderson's  Text-Book.  3.00 

Bulkley.    The  Skin.        -  .40 

Crocker.  Dis.  of  Skin.  Illus.  4.50 
Impey.  Leprosy.  -  -  3.50 
Van   Harlingen.     Diagnosis 

and  Treatment  of  Skin  Dis. 

3d  Ed.     60  Illus.      -        -        2.75 

STIMULANTS  &  NARCOTICS. 
Lizars.     On  Tobacco.      -  .40 

Parrish.  Inebriety.  -  i.oo 
SURGERY  AND  SURGICAL 

DISEASES. 
Caird  and  Cathcart.    Surg- 

geon's  Pocket  Book.  Lea.  2.50 
Deaver.    Appendicitis.        -     3.50 

burgical  Anatomy,      -    

Dulles.  Emergencies.  -  i.oo 
Hacker.  Wounds.  -  -  .50 
Heath's  Minor.    loth  Ed.         1.25 

Diseases  of  Jaws.       -     4.50 

Lectures  on  Jaws.  .50 

Horwitz.  Compend.   5th  Ed.     .80 
Jacobson.     Operations  of.   -     3.00 
Macready  on  Ruptures        -    6.00 
MouUin.      Complete     Text- 
book     3d   F.d.  by  Hamilton, 
600  Illustrations  and  Colored 
Plates.  Cl.  600:  Sh.    7.00 

Porter's    Surgeon's    Pocket- 
book.  -        -    Leather   2.00 

Smith.     Abdominal  Surg.        

Swain.  Surgical  Emer.  -  — — 
Voswinkel.  Surg  Nursing,  i  00 
■Walsham.  Practical  Surg.  2.75 
Watsofl's  Amputations.  5.50 


TECHNOLOGICAL  BOOKS. 
Cameron.  Oils  &  Varnishes.    2.25 

Soap  and  Candles.         2.00 

Gardner.     Brewing,  etc.         (1.50 
Gardner.    Bleaching    and 

Dyeing.    ....        1.50 
Groves  and  Thorp.    Chemi- 
cal   Technology.       Vol.     I. 
Mills  on  Fuels.  -         Cl.  5.00 

Vol.  II.     Lighting.  -         4.00 

Vol.  III.  Lighting  Contin'd.  ^— 
Overman.     Mineralogy.     -      i.oo 

THERAPEUTICS. 
Allen,  Harlan,  Harte,  Van 

Harlingen.  Local  Thera.  3.00 
Biddle.     13th  Edition  -      4  00 

Field.  Cathartics  and  Emetics.  1.75 
Mays.     Therap.  Forces.  1.25 

Theine         -        -        -         50 

Napheys'  Therapeutics.  Vol. 

I.     Medical  and   Disease  of 
Children.  -  Cloth,  4.00 

Vol.  2.  Surgery,  Gynaec. 

&  Obstet.  -  Cloth,  4.00 

Potter's  Compend.     5th  Ed.      .80 

,  Handbook  of.  4.00  ;  Sh.  5.00 

■Waring's  Practical.    4th  Ed.  2.C0 
White   and    Wilcox.    Mat. 
Med.,  Pharmacy,  Pharmacol- 
ogy, and  Thera.     3d  Ed.        2.75 
THROAT  AND  NOSE. 
Cohen.    Throat  and  Voice.        .40 
Hall.     Nose  and  Throat.    -      2.50 

Nose  and  Ear.  -  .80 

Hutchinson.  Nose  &  Throat. 
Mackenzie.    Throat  Hospital 

Pharmacopoeia.  5th  Ed.  i.oo 
McBride.      Clinical  Manual, 

Colored  Plates.  2d  Ed.  -  6.00 
Murrell.  Bronchitis.  -  1.50 
Potter.  Stammering,  etc.  i.oo 
Woakes.  Post-Nasal  Catarrh,  i.oo 

TRANSACTIONS. 
Trans.   Association  Amer. 

Physicians.  -      r-    3.50 

URINE  &  URINARY  ORGANS. 
Acton.     Repro.  Organs.  1.75 

Allen.     Diabetic  Urine.  2.25 

Beale.  Urin.  Deposits.  Plates.  1.75 
Holland.  The  Urine,  Milk  and 

Common  Poisons.    5th  Ed.     i.oo 

Legg.     On  Urine.    7th  Ed.        i.oo 

Memminger.     Diagnosis  by 

i       the  Urine.     Illus.    -        -         i.oo 

Moullin.     The  Prostate.     -    1.50 

!  Thompson.  Urinary  Organs.   3.00 

i  Calculous  Dis.  3d.  Ed.      .75 

'  Tyson.      Exam,   of  Urine.     1.25 
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i         VENEREAL  DISEASES. 
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Physiology  at  Jefferson  Medical  College,  Prof,  of  Physiology,  Penn'a  College  of 
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CLOWES  AND  COLEMAN.  Elementary  Qualitative  Analysis.  Adapted  for 
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COBLENTZ.  Manual  of  Pharmacy.  A  Text-Book  for  Students.  By  Virgil 
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COLLIE,  On  Fevers.  A  Practical  Treatise  on  Fevers,  Their  Histor}',  Etiology, 
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COPLIN  and  SEVAN.  Practical  Hygiene.  By  W.  ^L  L.  Coplik,  m.d..  Adjunct 
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R.\DCLIFFE  Crocker,  m.d.,  Physician  to  the  Dept.  of  Skin  Diseases,  University 
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CULLINGWORTH.    A  Manual  of  Nursing,  Medical  and  Surgical    By  Charles 

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Infancy  in  the  Philadelphia  Polyclinic,  Clinical  Lecturer  on  Obstetrics,  Jeffer- 
son Medical  College ;  Professor  of  Diseases  of  Children  in  Woman's  Medical 
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Deaver,  m  d.,  -Vssistant  Professor  of  Applied  Anatomy,  L^niversity  of  Pennsyl- 
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cavities  in  teeth  of  all  grades  of  structure.  By  J.  Foster  Flagg,  d.d.s..  Professor 
of  Dental  Pathology  in  Philadelphia  Dental  College.  Fourth  Revised  Edition. 
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FOWLEE'S  Dictionary  of  Practical  Medicine.  By  Various  IVriiers.  An  Ency- 
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FOX   AHD   GOULD.     Compend  on  Diseases  of  the  Eye  and  Eefraction, 

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"  Dictionary  of  Medical  Terminology  and  Dental  Surgery."  Thirteenth  Edition. 
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tions.   1 180  pages.    8vo.  Cloth,  $6.00 ;  Leather,  $7.00 

Dictionary  of  Dentistry.  Fifth  Edition,  Revised.  Including  Definitions  of 
such  Words  and  Phrases  of  the  Collateral  Sciences  as  Pertain  to  the  Art  and 
Practice  of  Dentistry.  Fifth  Edition.  Rewritten,  Revised  and  Enlarged. 
By  Ferdinand  J.  S.  Gorgas,  m.d.,  d.d.s..  Author  of  "Dental  Medicine;" 
Editor  of  Harris's  "Principles  and  Practice  of  Dentistry;"  Professor  of 
Principles  of  Dental  Science,  Dental  Surgery,  and  Prosthetic  Dentistry  in  the 
University  of  Maryland.     Octavo.  Cloth,  $4.50;  Leather,  $5.50 

HARRIS  and  BEALE.  Treatment  of  Pulmonary  Consumption.  By  Vincent 
Dormer  Harris,  m.d.  (Lond.),  f.r.c.p..  Physician  to  the  city  of  London  Hospi- 
tal for  Diseases  of  the  Chest ;  Examining  Physician  to  the  Royal  National  Hos- 
pital for  Diseases  of  the  Chest,  Ventnor,  etc.,  and  E.  Clifford  Beale,  m.a., 
m.b.  (Cantab.),  f.r.c.p..  Physician  to  the  city  of  London  Hospital  for  Diseases 
of  the  Chest,  and  to  th6  Great  Northern  Central  Hospital,  etc.  A  Practical 
Manual.     i2mo.  Cloth,  $2.50 

HARTRID6E.    Refraction.    The  Refraction  of  the  Eye.    A  Manual  for  Students. 
By  GusTAVus  Hartridge,  F.R.C.S.,  Consulting  Ophthalmic  Surgeon  to  St.  Bar- 
tholomew's Hospital ;  Ass't  Surgeon  to  the  Royal  Westminster  Ophthalmic  Hos- 
pital, etc.     98  Illustrations  and  Test  Types.     Seventh  Edition.  Cloth,  $1.00 
On  The  Ophthalmoscope.     A  Manual  for  Physicians  and  Students.     Second 
Edition.    With  Colored  Plates  and  many  Woodcuts.     i2mo.        Cloth,  $1.25 

HARTSHORNE.  Our  Homes.  Their  Situation,  Construction,  Drainage,  etc.  By 
Henry  Hartshorne,  m.d.     Illustrated.  Cloth,  .40 

HATFIELD.  Diseases  of  Children.  By  Marcus  P.  Hatfield,  Professor  ot 
Diseases  of  Children,  Chicago  Medical  College.  With  a  Colored  Plate.  Second 
Edition.     Being  No.  14,  f  Quiz- Compend  ?  Series.     i2mo.  Cloth,  .80 

Interleaved  for  the  addition  of  notes,  $1.25 

HEATH.    Minor  Surgery  and  Bandaging.    By  Christopher  Heath,  f.r.c.s., 

Holme   Professor  of  Clinical   Surgery   in   University  College,  London.     Tenth 

Edition.      Revised  and   Enlarged.     With   158    Illustrations,  62   Formulce,  Diet 

List,  etc.     i2mo.  Cloth,  $1.2'^ 

Practical  Anatomy.      A  Manual  of  Dissections.      Eighth  London  Edition. 

300  Illustrations.  Cloth,  $4.25 

Injuries  and  Diseases  of  the  Jaws.    Fourth  Edition.    Edited  by  Henry 

Percy   Dean,    m.s.,  f.r.c.s.,  Assistant   Surgeon    London  Hospital.     With 

187  Illustrations.    8vo.  Cloth,  $4.50 

Lectures  on  Certain  Diseases  of  the  Jaws,  delivered  at  the  Royal  College  of 
Surgeons  of  England,  1887.     64  Illustrations.     Svo.  Boards,  .50 

HENRY.  Anaemia.  A  Practical  Treatise.  By  Fred'k  P.  Henry,  m.d..  Physician 
to  Episcopal  Hospital,  Philadelphia.  Half  Cloth,  .50 


14  P.  BLAKISTON,  SON  &*  CO.'S 

HOLDEN'S  Anatomy.  Sixth  Edition.  A  Manual  of  the  Dissections  of  the  Human 
Body.  By  John  Langton,  f.r.c.s.,  Surgeon  to,  and  Lecturer  on  Anatomy  at, 
St.  Bartholomew's  Hospital.  Carefully  Revised  by  A.  Hewson,  m.d..  Demonstra- 
tor of  Anatomy,  Jefferson  Medical  College;  Chief  of  Surgical  Clinic,  Jefferson 
Hospital;  Mem.  Assoc.  Amer.  Anatomists,  etc.  311  Illustrations.  i2mo.  8co 
pages.  Cloth,  $2.50;  Oil-cloth,  $2.50;  Leather,  $3.00 

Human  Osteology.  Comprising  a  Description  of  the  Bones,  with  Colored 
Delineations  of  the  Attachments  of  the  Muscles.  The  General  and  Micro- 
scopical Structure  of  Bone  and  its  Development.  Carefully  Revised,  by 
the  Author  and  Prof.  Stewart,  of  the  Royal  College  of  Surgeons'  Museum. 
With  Lithographic  Plates  and  Numerous  Illustrations.  7th  Ed.  Cloth,  $5.25 
Landmarks.     Medical  and  Surgical.     4th  Edition.     8vo.  Cloth,  ^i.cxa 

HOLLAND.  The  Urine,  the  Gastric  Contents,  the  Common  Poisons  and  the 
Milk.  Memoranda,  Chemical  and  Microscopical,  for  Laboratory  Use.  By  J.  W. 
Holland,  m.d..  Professor  of  Medical  Chemistry  and  Toxicology  in  Jefferson 
Medical  College,  of  Philadelphia.  Fifth  Edition,  Enlarged.  Illustrated  and 
Interleaved.  i2mo.  Cloth,  $1.00 

HORSLET.  The  Brain  and  Spinal  Cord.  The  Structure  and  Functions  of.  Being 
the  FuUerian  Lectures  on  Physiology  for  1891.  By  Victor  A.  Horsley,  m.b., 
F.R.S.,  etc..  Assistant  Surgeon,  University  College  Hospital,  Professor  of  Pathology, 
University  College,  London,  etc.     With  numerous  Illustrations.  Cloth,  $2.50 

HORWITZ'S  Compend  of  Surgery,  including  Minor  Surgery,  Amputations,  Frac- 
tures, Dislocations,  Surgical  Diseases,  and  the  Latest  Antiseptic  Rules,  etc.,  with 
Differential  Diagnosis  and  Treatment.  By  Orville  Horwitz,  b.s.,  m.d..  Pro- 
fessor of  Genito-Urinary  Diseases,  late  Demonstrator  of  Surgery,  Jefferson  Medi- 
cal College.  Fifth  Edition.  Very  much  Enlarged  and  Rearranged.  Over  300 
pages.     167  Illustrations  and  98  Formulae.    i2mo.  No.  g  ? Quiz- Compend?  Series. 

Cloth,  .80.     Interleaved  for  notes,  $1.25 

HOVELL.  Diseases  of  the  Ear  and  Naso-Pharynx.  A  Treatise  including 
Anatomy  and  Physiology  of  the  Organ,  together  with  the  treatment  of  the  affec- 
tions of  the  Nose  and  Pharynx  which  conduce  to  aural  disease.  By  T.  Mark 
Hovell,  f.r.c.s.  (Edin.),  m.r.c.s.  (Eng.),  Aural  Surgeon  to  the  London  Hospital, 
to  Hospital  for  Diseases  of  the  Throat,  and  to  British  Hospital  for  Incurables, 
etc.     122  Illustrations.     Octavo.  Cloth,  $5.00 

HTIQHES.  Compend  of  the  Practice  of  Medicine.  Fifth  Edition.  Revised  and 
Enlarged.  By  Daniel  E.  Hughes,  m.d..  Demonstrator  of  CHnical  Medicine  at 
Jefferson  Medical  College,  Philadelphia.  In  two  parts.  Being  Nos.  2  and  j, 
•  Quiz-  Compend  ?  Series. 

Part  I. — Continued,  Eruptive  and  Periodical  Fevers,  Diseases  of  the  Stomach, 
Intestines,  Peritoneum,  Biliary  Passages,  Liver,  Kidneys,  etc.,  and  General 
Diseases,  etc. 

Part  II. — Diseases  of  the  Respiratory  System,  Circulatory  System  and  Ner- 
vous System  ;  Diseases  of  the  Blood,  etc. 

Price  of  each  Part,  in  Cloth,  .80 ;  interleaved  for  the  addition  of  Notes,  $1.25 
Physicians'  Edition. — In  one  volume,  including  the  above  two  parts,  a  sec- 
tion on  Skin  Diseases,  and  an  index.      Fifth  revised,  enlarged  Edition. 
^68 pages.  Full  Morocco,  Gilt  Edge,  J52.25 

"  Carefully  and  systematically  compiled." — The  London  Lancet. 
HUMPHREY.  A  Manual  for  Nurses.  Including  general  Anatomy  and  Physiology, 
management  of  the  sick-room,  etc.  By  Laurence  Humphrey,  m.a.,  m.b., 
m.r.c.s.,  Assistant  Physician  to,  and  Lecturer  at,  Addenbrook's  Hospital,  Cam- 
bridge, England.  Thirteenth  Edition.  i2mo.  Illustrated.  Cloth,  $1.00 
HYSLOP'S  MENTAL  PHYSIOLOGY.  Especially  in  its  Relation  to  Mental  Dis- 
orders. By  Theo.  B.  Hyslop,  m.d..  Lecturer  on  Mental  Diseases,  St.  Mary's 
Hospital  Medical  School,  Assistant  Physician,  Bethlem  Royal  Hospital,  London. 
With  Illustrations.     i2mo.  Cloth,  $4.25 


MEDICAL  AND  SCIENTIFIC  PUBLICA  TIONS.  15 

HUTCHINSON.  The  Nose  and  Throat.  A  Manual  of  the  Diseases  of  the  Nose 
and  Throat,  including  the  Nose,  Naso-Pharynx,  Pharynx  and  Larynx.  By 
Procter  S.  Hutchinson,  m.r.c.s.,  Ass't  Surgeon  to  the  London  Hospital  for 
Diseases  of  the  Throat.  Illustrated  by  Lithograph  Plates  and  40  other  Illus., 
many  of  which  have  been  made  from  original  drawings.    i2mo.    2d  Ed.    In  Press. 

IMPEY.  A  Handbook  on  Leprosy.  By  S.  P.  Impey,  m.d.,  m.c,  Late  Chief  and 
Medical  Superintendent,  Robben  Island  Leper  and  Lunatic  Asylums,  Cape  Col- 
ony, South  Africa.     Illustrated  by  37  Plates  and  a  Map.     Octavo.      Cloth,  $3.50 

JACOBSON.  Operations  of  Surgery.  By  W.  H.  A.  Jacobson,  b.a.  oxon., 
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Children  and  Women,  etc.     With  over  200  lllust.      Cloth,  $3.00  ;  Leather,  54-oo 

Diseases  of  the  Male  Organs  of  Generation.    88  Illustrations.    Cloth,  $6.00 

JONES.  Medical  Electricity.  A  Practical  Handbook  for  Students  and  Prac- 
titioners of  Medicine.  By  H.  Lewis  Jones,  m.a.,  m.d.,  m.r.c.p.,  Medical  Officer 
in  Charge  Electrical  Department,  St.  Bartholomew's  Hospital.  Second  Edition 
of  Steavenson  and  Jones'  Medical  Electricity.  Revised  and  Enlarged.  112  Illus- 
trations.    i2mo.  Cloth,  $2.50 

KENWOOD.  Public  Health  Laboratory  "Work.  By  H.  R.  Kenwood,  m.b., 
D.P.H.,  F.C.S.,  Instructor  in  Hygienic  Laboratory,  University  College,  late  Assistant 
Examiner  in  Hygiene,  Science  and  Art  Department,  South  Kensington,  London, 
etc.     With  116  Illustrations  and  3  Plates.  Cloth,  $2.00 

KIRKES'  Physiologry.  (/?//«  Atithorized  Edition.  i2mo.  Dark  Red  Cloth.) 
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By  W.  MoRRANT  Baker,  m.d.,  and  Vincent  Dormer  Harris,  m.d.  516  Illus- 
trations, some  of  which  are  printed  in  Colors.  i2mo.  Cloth,  $3.25  ;  Leather,  54.00 

ELEEN.  Handbook  of  Massage.  By  Emil  Kleen,  m.d.,  ph.d.,  Stockholm  and 
Carlsbad.  Authorized  Translation  from  the  Swedish,  by  Edward  Mussey  Hart- 
well,  M.D.,  PH.D.,  Director  of  Physical  Training  in  the  Public  Schools  of  Boston. 
With  an  Introduction  by  Dr.  S.  Weir  Mitchell,  of  Philadelphia.  Illustrated 
with  a  series  of  Photographs  made  specially  by  Dr.  Kleen  for  the  American 
Edition.     Svo.  Cloth,  $2.25 

LANDIS'  Compend  of  Obstetrics  ;  especially  adapted  to  the  Use  of  Students  and 
Physicians.  By  Henry  G.  Landis,  m.d.  Fifth  Edition.  Revised  by  Wm.  H. 
Wells,  m.d.,  Ass't  Demonstrator  of  Clinical  Obstetrics,  Jefferson  Medical  College ; 
Member  Obstetrical  Society  of  Philadelphia,  etc.  Enlarged.  With  Many  Illus- 
trations.    No.  ^  ? Quiz- Compend?  Series. 

Cloth,  .80;  interleaved  for  the  addition  of  Notes,  $1.25 

LANDOIS.  A  Text-Book  of  Human  Physiology ;  including  Histology  and  Micro- 
scopical Anatomy,  with  special  reference  to  the  requirements  of  Practical  Medi- 
cine. By  Dr.  L.  Landois,  Professor  of  Physiology  and  Director  of  the  Physio- 
logical Institute  in  the  University  of  Greifswald.  Fifth  American,  translated 
from  the  last  German  Edition,  with  additions,  by  Wm.  Stirling,  m.d.,  d.Sc, 
Brackenbury  Professor  of  Physiology  and  Histology  in  Owen's  College,  and  Pro- 
fessor in  Victoria  University,  Manchester  ;  Examiner  in  Physiology  in  University 
of  Oxford,  England.  With  845  Illustrations,  many  of  which  are  printed  in 
Colors.     Svo.  In  Press. 

LEE.  The  Microtomist's  Vade  Mecum.  Fourth  Edition.  A  Handbook  of 
Methods  of  Microscopical  Anatomy.  By  Arthur  Bolles  Lee,  Ass't  in  the  Rus- 
sian Laboratory  of  Zoology,  at  Villefranche-sur-Mer  (Nice).  881  Articles.  En- 
larged and  Revised.     Octavo.  In  Press. 


16  P.  BLAKISTON,  SON  d-  CO.'S 


LEFFMANN'S  Compend  of  Medical  Chemistry,  Inorganic  and  Organic.  In- 
cluding Urine  Analysis.  By  Henry  Leffmann,  m.d.,  Prof,  of  Chemistry  and 
Metallurgy  in  the  Penna.  College  of  Dental  Surgery  and  in  the  Wagner  Free 
Institute  of  Science,  Philadelphia.  No.  lo  ? Quiz- Compend  f  Series.  Fourth 
Edition.    Rewritten.  Cloth,  .80.    Interleaved  for  the  addition  of  Notes,  $1.25 

The  Coal-Tar  Colors,  with  Special  Reference  to  their  Injurious  Qualities  and 
the  Restrictions  of  their  Use.  A  Translation  of  Theodore  Weyl's  Mono- 
graph.    i2mo.  Cloth,  $1.25 

Progressive  Exercises  in  Practical  Chemistry.  A  Laboratory  Handbook. 
Illustrated.     Third  Edition,  Revised  and  Enlarged.     i2mo.      Cloth,  Ji.cxj 

Examination  of  Water  for  Sanitary  and  Technical  Purposes.  Third  Edition. 
Enlarged.     Illustrated.     i2mo.  Cloth,  $1.25 

Analysis  of  Milk  and  Milk  Products.    Arranged  to  suit  the  needs  of  Analyt- 
ical Chemists,  Dairymen,  and  Milk  Inspectors.     i2mo.  Cloth,  $1.25 
LEGO   on  the  Urine.      Practical    Guide   to   the   Examination    of  Urine.      By  J. 
WiCKHAM  Legg,  m.d.     Seventh  Edition,  Enlarged.     Edited  and  Revised  by  H. 
Lewis  Jones,  m.a.,  m.d.,  m.r.c.p.     Illustrated.     i2mo.  Cloth,  gi.oo 
LEWERS.    On  the  Diseases  of  Women.    A  Practical  Treatise.    By  Dr.  A.  H. 
N.  Lewers,  Assistant  Obstetric  Physician  to  the  London  Hospital ;  and  Phy- 
sician to  Out-patients,  Queen  Charlotte's  Lying-in  Hospital;  Examiner  in  Mid- 
wifery and  Diseases  of  Women  to  the  Society  of  Apothecaries  of  London.     With 
146  Engravings.     Third  Edition,  Revised.                                                Cloth,  $2.00 
LEWIS  (BEVAN).    Mental  Diseases.  A  text-book  having  special  reference  to  the 
Pathological  aspects  of  Insanity.     By  Bevan  Lewis,   l.r.c.p.,  m.r.c.s..  Medi- 
cal Director,  West  Riding  Asylum,  Wakefield,  England.     18  Lithographic  Plates 
and  other  Illustrations.     Second  Edition.     8vo.  In  Press. 
LINCOLN.    School  and  Industrial  Hygiene.    By  D.  F.  Lincoln,  m.d.    Cloth,  .40 
LIZARS  (JOHN).     On  Tobacco.     The  Use  and  Abuse  of  Tobacco.           Cloth,  .40 
LONGLET'S  Pocket  Medical  Dictionary  for  Students  and  Physicians.    Giving 
the  Correct  Definition  and  Pronunciation  of  all  Words  and  Terms  in  General 
Use  in  Medicine   and  the  Collateral   Sciences,  with   an  Appendix,  containing 
Poisons  and  their  Antidotes,  Abbreviations  Used  in  Prescriptions,  and  a  Metric 
Scale  of  Doses.     By  Elias  Longley.            Cloth,  .75  ;  Tucks  and  Pocket,  j^i.oo 

MACALISTER'S  Human  Anatomy.  800  lUustrations.  A  New  Text-book  for 
Students  and  Practitioners.  Systematic  and  Topographical,  including  the 
Embryology,  Histology  and  Morphology  of  Man.  With  special  reference  to  the 
requirements  of  Practical  Surgery  and  Medicine.  By  Alex.  Macalister,  m.d., 
F.R.S.,  Professor  of  Anatomy  in  the  University  of  Cambridge,  England ;  Examiner 
in  Zoology  and  Comparative  Anatomy,  University  of  London ;  formerly  Professor 
of  Anatomy  and  Surgery,  University  of  Dublin.  With  816  Illustrations,  400  of 
which  are  original.     Octavo.  Cloth,  $5.00;  Leather,  $6.co 

MACDONALD'S  Microscopical  Examinations  of  Water  and  Air.  With  an  Ap- 
pendix on  the  Microscopical  Examination  of  Air.  By  J.  D.  Macdonald,  m.d. 
25  Lithographic  Plates,  Reference  Tables,  etc.     Second  Ed.     8vo.     Cloth,  $2.50 

MACKENZIE.  The  Pharmacopoeia  of  the  London  Hospital  for  Diseases  of 
the  Throat.  By  Sir  Morell  Mackenzie,  m.d.  Fifth  Edition.  Revised  and 
Improved  by  F.  G.  Harvey,  Surgeon  to  the  Hospital.  Cloth,  Ji.oo 

MACNAMARA.  On  the  Eye.  A  Manual.  By  C.  Macnamara,  m.d.  Fifth 
Edition,  Carefully  Revised ;  with  Additions  and  Numerous  Colored  Plates,  Dia- 
grams of  Eye,  Wood-cuts,  and  Test  Types.     Demi  8vo.  Cloth,  $3.50 


MEDICAL  AND  SCIENTIFIC  PUBLIC  A  TIONS.  17 

MACREADY.  A  Treatise  on  Ruptures.  By  Jonathan  F.  C.  H.  Macready, 
F.K.C.S.,  Surgeon  to  the  Great  Northern  Central  Hospital;  to  the  City  of  London 
Hospital  for  Diseases  of  the  Chest;  to  the  City  of  London  Truss  Society,  etc. 
With  24  full-page  Lithographed  Plates  and  numerous  Wood-Engravings.  Octavo. 

Cloth,  $6.00 

MANN.  Forensic  Medicine  and  Toxicology.  A  Text-Book  by  J.  Dixon  Mann, 
M.D.,  F.R.C.P.,  Professor  of  Medical  Jurisprudence  and  Toxicology  in  Owens  Col- 
lege, Manchester ;  Examiner  in  Forensic  Medicine  in  University  of  London,  etc. 
Illustrated.     Octavo.  Cloth,  ^6.50 

MANN'S  Manual  of  Psychological  Medicine  and  Allied  Nervous  Diseases.  Their 
Diagnosis,  Pathology,  Prognosis  and  Treatment,  including  their  Medico-Legal 
Aspects  ;  with  chapter  on  Expert  Testimony,  and  an  abstract  of  the  laws  relating 
to  the  Insane  in  all  the  States  of  the  Union.  By  Edward  C.  Mann,  m.d., 
member  of  the  New  York  County  Medical  Society.  With  Illustrations  of  Typical 
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the  Class.  By  John  Marshall,  f.r.s.,  f.r.c.s..  Professor  of  Anatomy  to  the 
Royal  Academy ;  Professor  of  Surgery,  University  College,  London,  etc. 

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ents. No.  6— The  Digestive  Organs.  No.  7 — The  Brain  and  Nerves.  Nos.  8  and  9 — 
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MASON'S  Compend  of  Electricity,  and  its  Medical  and  Surgical  Uses.  By 
Charles  F.  Mason,  m.d..  Assistant  Surgeon  U.  S.  Army.  With  an  Intro- 
duction by  Charles  H.  May,  m.d..  Instructor  in  the  New  York  Polyclinic. 
Numerous  Illustrations.     i2mo.  Cloth,  .75 

MAXWELL.  Terminologia  Medica  Polyglotta.  By  Dr.  Theodore  Maxwell, 
assisted  by  others  in  various  countries.     8vo.  Cloth,  $3.00 

The  object  of  this  work  is  to  assist  the  medical  men  of  any  nationality  in  reading  medical  literature  written 
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Italian,  Spanish,  Russian  and  Latin. 

MAYS'  Therapeutic  Forces  ;  or.  The  Action  of  Medicine  in  the  Light  of  the  Doc- 
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Theine  in  the  Treatment  of  Neuralgia.    i6mo.                        ]i  bound,  .50 

McBRIDE.  Diseases  of  the  Throat,  Nose  and  Ear.  A  Clinical  Manual  for  Stu- 
dents and  Practitioners.  By  P.  McBride,  m.d.,  f.r.c.p.  (Edin.),  Surgeon  to  the 
Ear  and  Throat  Department  of  the  Royal  Infirmary;  Lecturer  on  Diseases  of 
Throat  and  Ear,  Edinburgh  School  of  Medicine,  etc.  With  Colored  Illustrations 
from  Original  Drawings.    2d  Edition.    Octavo.       Handsome  Cloth,  Gilt  top,  $6.00 

McNEILL.  The  Prevention  of  Epidemics  and  the  Construction  and  Man- 
agement of  Isolation  Hospitals.  By  Dr.  Roger  McNeill,  Medical  Officer  of 
Health  for  the  County  of  Argyll.  With  numerous  Plans  and  other  Illustrations. 
Octavo.  Cloth,  $3.50 


18  P.  PLAKISTON,  SON  6-  CO:S 

M EIOS.  Milk  Analysis  and  Infant  Feeding^.  A  Treatise  on  the  Examination  of 
Human  and  Cows'  Milk,  Cream,  Condensed  Milk,  etc.,  and  Directions  as  to  the 
Diet  of  Young  Infants.     By  Arthur  V.  Meigs,  m.d,     i2mo.  Cloth,  .50 

MEMMINGER.  Diagnosis  by  the  Urine.  The  Practical  Examination  of  Urine, 
with  Special  Reference  to  Diagnosis.  By  Allard  Memminger,  m.d.,  Professor 
of  Chemistry  and  of  Hygiene  in  the  Medical  College  of  the  State  of  S.  C. ;  Visiting 
Physician  in  the  City  Hospital  of  Charleston,  etc.    23  lUus.    i2mo.     Cloth,  $1.00 

MEYER.  Ophthalmology.  A  Manual  of  Diseases  of  the  Eye.  By  Dr.  Edouard 
Meyer.  Translated  from  the  Third  French  Edition  by  A.  Freedland  Fer- 
gus, m.b.     270  Illustrations,  two  Colored  Plates.         Cloth,  $3.50;  Leather,  $4.50 

MONEY.  On  Children.  Treatment  of  Disease  in  Children,  including  the  Outlines 
of  Diagnosis  and  the  Chief  Pathological  Differences  between  Children  and 
Adults.  By  Angel  Money,  m.d.,  m.r.c.p.,  Ass't  Physician  to  the  Hospital  for 
Sick  Children,  Great  Ormond  St.,  London.     2d  Edition.     i2mo.         Cloth,  $2.50 

MORRIS.  Text-Book  of  Anatomy.  791  Illustrations,  many  in  Colors.  A  com- 
plete Text-book.  Edited  by  Henry  Morris,  f.r.c  s.,  Surg,  to,  and  Lect.  on 
Anatomy  at,  Middlesex  Hospital,  assisted  by  J.  Bland  Sutton,  f.r  c.s.,  J.  H. 
Davies-Colley,  F.R.C.S.,  Wm.  J.  Walsham,  F.R.C.S.,  H.  St.  John  Brooks,  m.d., 
R.  Marcus  Gunn,  f.r.c.s.,  Arthur  Hensman,  f.r. c.s.,  Frederick  Treves, 
F.R.C. s.,  William  Anderson,  f.r.c.s.,  and  Prof.  W.  H.  A.  Jacobson.  One 
Handsome  Octavo  Volume,  with  791  Illustrations,  214  of  which  are  printed  in 
colors.  Cloth,  $6.00;  Leather,  $7. CO ;  Half  Russia,  $8.00 

"Taken  as  a  whole,  we  have  no  hesitation  in  according  very  high  praise  to  this  work.     It 

will  rank,  we  believe,  with  the  leading  Anatomies.     The  illustrations  are  handsome  and  the 

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Handsome  circular,  with  sample  pages  and  colored  illustrations,  will  be  sent  free 
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MOULLIN.  Surgery.  Third  Edition,  by  Hamilton.  A  Complete  Text-book. 
By  C.  W.  Mansell  Moullin,  m.a.,  m.d.  oxon.,  f.r.c.s..  Surgeon  and  Lec- 
turer ori  Physiology  to  the  London  Hospital ;  formerly  Radcliffe  Traveling 
Fellow  and  Fellow  of  Pembroke  College,  Oxford.  Third  American  Edition. 
Revised  and  edited  by  John  B.  Hamilton,  m.d.,  ll.d..  Professor  of  the  Principles 
of  Surgery  and  Clinical  Surgery,  Rush  Medical  College,  Chicago  ;  Professor  of 
Surgery,  Chicago  Polyclinic  ;  Surgeon,  formerly  Supervising  Surgeon-General, 
U.  S.  Marine  Hospital  Service ;  Surgeon  to  Presbyterian  Hospital ;  Consulting 
Surgeon  to  St.  Joseph's  Hospital  and  Central  Free  Dispensary,  Chicago,  etc. 
600  Illustrations,  over  200  of  which  are  original,  and  many  of  which  are  printed 
in  Colors.     Royal  Octavo.     1250  pages. 

Handsomely  bound  in  Cloth,  $6.00 ;  Leather,  $7.00 
"  The  aim  to  make  this  valuable  treatise  practical  by  giving  special  attention  to  questions  of 
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of  satisfaction  that  his  wants  have  been  understood,  and  that  they  have  been  intelligently  met. 
He  will  not  look  in  vain  for  details,  without  proper  attention  to  which  he  well  knows  that  the 
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Enlargement  of  the   Prostate.     Its  Treatment  and   Radical   Cure.     Illus- 
trated.    Octavo.  Cloth,  $1.50 
MTJRRELL.    Massotherapeutics.    Massage  as  a  Mode  of  Treatment.    By  Wm. 
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minster Hospital.     Fifth  Edition.    Revised.    i2mo.  Cloth,  $1.25 
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Study.     i2mo.     176  pages.  Cloth,  $150 
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MORTON  on  Refraction  of  the  Eye.  Its  Diagnosis  and  the  Correction  of  its  Errors. 
With  Chapter  on  Keratoscopy,  and  Test  Types.  By  A.  Morton,  m.b.  Fifth 
Edition,  Revised  and  Enlarged.  Cloth,  $i.oo 

MUSKETT.  Prescribing  and  Treatment  in  the  Diseases  of  Infants  and  Child- 
ren. By  Philip  E.  Mltskett,  Late  Surgeon  to  the  Sydney  Hospital,  Formerly 
Senior  Resident  Medical  Officer,  Sydney  Hospital.     32mo.  Cloth,  $1.25 

MUTER.  Practical  and  Analytical  Chemistry.  By  John  Muter,  f.r.s.,  f.c.s., 
etc.  Fourth  Edition.  Revised,  to  meet  the  requirements  of  American  Medical 
Colleges,  by  Claude  C.  Hamilton,  m.d..  Professor  of  Analytical  Chemistry 
in  University  Med.  Col.  and  Kansas  City  Col.  of  Pharmacy.     51  Illus.    Cloth,  $1.25 

NAPHEYS'  Modern  Therapeutics.  Ninth  Revised  Edition,  Enlarged  and  Im- 
proved. In  Two  Handsome  Volumes.  Edited  by  Allen  J.  Smith,  m.d..  Pro- 
fessor of  Pathology,  University  of  Texas,  Galveston,  late  Ass't  Demonstrator  of 
Morbid  Anatomy  and  Pathological  Histology,  Lecturer  on  Urinology,  University 
of  Pennsylvania ;  and  J.  Aubrey  Davis,  m.d.,  Ass't  Demonstrator  of  Obstetrics, 
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NOTTER  and  FIRTH.  The  Theory  and  Practice  of  Hygiene.  A  Complete 
Treatise  by  J.  Lane  Notter,  m.a.,  m.d.,  f.c.s..  Fellow  and  Member  of  Council 
of  the  Sanitary  Institute  of  Great  Britain  ;  Professor  of  Hygiene,  Army  Medical 
School ;  Examiner  in  Hygiene,  University  of  Cambridge,  etc.,  and  R.  H.  Firth, 
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OBERSTEINER.  The  Anatomy  of  the  Central  Nervous  Organs.  A  Guide  to  the 
study  of  their  structure  in  Health  and  Disease.  By  Professor  H.  Obersteiner, 
of  the  University  of  Vienna.  Translated  and  Edited  by  Alex.  Hill,  m.a.,  m.d., 
Master  of  Downing  College,  Cambridge.     198  Illustrations.     8vo.       Cloth,  $5.50 

OHLEMANN.  Ocular  Therapeutics  for  Physicians  and  Students.  By  M.  Ohle- 
mann,  m.d.  Translated  and  Edited  by  Charles  A.  Oliver,  a.m.,  m.d.,  Attend- 
ing Surgeon  to  Wills  Eye  Hospital,  Ophthalmic  Surgeon  to  the  Philadelphia  and 
to  the  Presbyterian  Hospitals,  Fellow  of  the  College  of  Physicians  of  Phila- 
delphia, etc.  In  Press. 

OPHTHALMIC  REVIEW.  A  Monthly  Record  of  Ophthalmic  Science.  Published 
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ORMEROD.  Diseases  of  Nervous  System,  Student's  Guide  to.  By  J.  A.  Ormerod, 
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8vo.  Cloth,  $2.00 

Chorea  and  Choreiform  Affections.    8vo.  Cloth,  $2.00 


20  P.  BLAKISTON,  SON  Sr»  CO.'S 

OSTROM.  Massage  and  the  Original  Swedish  Movements.  Their  Application 
to  Various  Diseases  of  the  Body.  A  Manual  for  Students,  Nurses  and  Physicians, 
By  KuRRE  W.  OsTROM,  from  the  Royal  University  of  Upsala,  Sweden;  Instructor 
in  Massage  and  Swedish  Movements  in  the  Hospital  of  the  University  of 
Pennsylvania,  and  in  the  Philadelphia  Polyclinic  and  CoUegafor  Graduates  in 
Medicine,  etc.  Third  Edition.  Enlarged.  Illustrated  by  94  Wood  Engrav- 
ings, many  of  which  were  drawn  especially  for  this  purpose.    i2mo.     Cloth,  $1.00 

OVERMAN'S  Practical  Mineralogy,  Assaying  and  Mining,  with  a  Description  of 
the  Useful  Minerals,  etc.  By  Frederick  Overman,  Mining  Engineer.  Elev- 
enth Edition.     i2mo.  Cloth,  $1.00 

PACKARD'S  Sea  Air  and  Sea  Bathing.    By  John  H.  Packard,  m.d.     Cloth,  .40 

PAGE.     Railroad  Injuries.     With  Special  Reference  to  those  of  the   Back  and 

Nervous  System.     By  Herbert  Page,  f.r.c.s.,  Surgeon  to  St.  Mary's  Hospital, 

and  Lecturer  on  Surgery  at  its  Medical  School.     Octavo.  Cloth,  $2.25 

Injuries  of  the  Spine  and  Spinal  Cord.     In  their  Surgical  and  Medico-Legal 

Aspects.     Third  Edition.     Revised.     Octavo.  Preparing. 

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"  Notter  and  Firth  "  Treatise  on  Hygiene.     See  previous  page. 

PARKES.     Hygiene  and  Public  Health.     A  Practical  Manual.     By  Louis  C. 

Parkes,  m.d.,  d.p.h.  London  Hospital;  Assistant  Professor  of  Hygiene   and 

Public  Health  at  University  College,  etc.    Fourth  Edition,  Enlarged  and  Revised. 

80  Illustrations.     i2mo.  Cloth,  $2.50 

The    Elements    of   Health.      An   Introduction   to  the  Study   of  Hygiene. 

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PARRISH'S  Alcoholic  Inebriety.  From  a  Medical  Standpoint,  with  Illustrative 
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PARVIN'S  Winckel's  Diseases  of  "Women.    (See  Winckel,  page  28.) 

PHILLIPS.  Spectacles  and  Eyeglasses,  Their  Prescription  and  Adjustment.  By 
R.  J.  Phillips,  m.d..  Instructor  on  Diseases  of  the  Eye,  Philadelphia  Polyclinic, 
Ophthalmic  Surgeon,  Presbyterian  Hospital.  Second  Edition,  Revised  and 
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PHYSICIAN'S  VISITING  LIST.  Published  Annually.  Forty-fifth  Year  (1896) 
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Compend  of  Anatomy,  including  Visceral  Anatomy.  Fifth  Edition.  Re- 
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Consulting  Physician  to  the  Hospital  for  Consumption  and  Diseases  of  the  Chest 
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22  P.  BLAKISTON,  SON  &*  CO:S 

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REG-IS.  Mental  Medicine.  A  Practical  Manual.  By  Dr.  E.  Ricis,  formerly 
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Edition.     Authorized  Translation  by  Edgar  F.  Smith,  m.a.,  ph.d..  Prof,  of 

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London.    Ninth  Edition,  with  Illustrations.    8vo.        Cloth,  $4. 50;  Leather,  1:5.50 

ROBINSON.  Latin  Grammar  of  Pharmacy  and  Medicine  By  D.  H.  Robinson, 
PH.D.,  Professor  of  Latin  Language  and  Literature,  University  of  Kansas.  Intro- 
duction by  L.  E.  Sayre,  ph.g..  Professor  of  Pharmacy  in,  and  Dean  of  the  Dept. 
of  Pharmacy,  University  of  Kansas.     i2mo.     Second  Edition.  Cloth,  $1.75 


MEDICAL  AND  SCIENTIFIC  PUBLICA  TIONS.  23 

SCOVILLE.  The  Art  of  Compounding.  A  Text-book  for  Students  and  a  Refer- 
ence Book  for  Pharmacists.  By  Wilbur  L.  Scoville,  ph.g.,  Professor  of  Ap- 
plied Pharmacy  and  Director  of  the  Pharmaceutical  Laboratory  in  the  Massa- 
chusetts College  of  Pharmacy.  Cloth,  $2.50 

SANSOM.  Diseases  of  The  Heart.  The  Diagnosis  and  Pathology  of  Diseases  of 
the  Heart  and  Thoracic  Aorta.  By  A.  Ernest  Sansom,  m.d.,  f.r.c.p.,  Physician 
to  the  London  Hospital,  Examiner  in  Medicine  Royal  College  of  Physicians,  etc. 
With  Plates  and  other  Illustrations.     8vo.  Cloth,  $6.00 

SAYRE.  Organic  Materia  Medica  and  Pharmacognosy.  An  Introduction 
to  the  Study  of  the  Vegetable  Kmgdom  and  the  Vegetable  and  Animal  Drugs. 
Comprising  the  Botanical  and  Physical  Characteristics,  Source,  Constituents,  and 
Pharmacopoeial  Preparations.  With  Chapters  on  Synthetic  Organic  Remedies, 
Insects  Injurious  to  Drugs,  and  Pharmacal  Botany.  By  L.  E.  Sayre,  ph.g., 
Professor  of  Pharmacy  and  Materia  Medica  in  the  University  of  Kansas,  Mem- 
ber of  the  Committee  of  Revision  of  the  U.  S.  Pharmacopoeia,  1890.  A  Glossary 
and  543  Illustrations,  many  of  which  are  original.     8vo.  Cloth,  $4.00 

SCHTJLTZE.  Obstetrical  Diagrams.  Being  a  Series  of  20  Colored  Lithograph 
Charts,  imperial  map  size,  of  Pregnancy  and  Midwifery,  with  accompanying 
explanatory  (German)  text,  illustrated  by  wood-cuts.  By  Dr.  B.  S.  Schultze, 
Professor  of  Obstetrics,  University  of  Jena.     Second  Revised  Edition. 

Price,  in  Sheets,  $26.00 ;  Mounted  on  Rollers,  Muslin  Backs,  $36.00 

SEWELL.  Dental  Surgery,  including  Special  Anatomy  and  Surgery.  By  Henry 
Sewell,  M.R.C.S.,  L.D.S.,  President  Odontological  Society  of  Great  Britain.  3d 
Edition,  greatly  enlarged,  with  about  200  Illustrations.  Cloth,  $2.00 

SHAWE.  Notes  for  Visiting  Nurses,  and  all  those  interested  in  the  working  and 
organization  of  District,  Visiting,  or  Parochial  Nurse  Societies.  By  Rosilind 
Gillette  Shawe,  District  Nurse  for  the  Brooklyn  Red  Cross  Society.  With  an 
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SMITH.  Abdominal  Surgery.  Being  a  Systematic  Description  of  all  the  Princi- 
pal Operations.  By  J.  Greig  Smith,  m.a.,  f.r.s.e.,  Surg,  to  British  Royal  In- 
firmary ;  Lecturer  on  Surgery,  Bristol  Medical  School ;  Late  Examiner  in  Surgery, 
University  of  Aberdeen,  etc.   Over  80  Illustrations.    Fifth  Edition.        Preparing. 

SMITH.  Electro-Chemical  Analysis.  By  Edgar  F.  Smith,  Professor  of  Chem- 
istry, University  of  Pennsylvania.  Second  Edition,  Revised  and  Enlarged.  28 
Illustrations.     i2mo.  Cloth,  $1.25 

SMITH  AND  KELLER.  Experiments.  Arranged  for  Students  in  General  Chem- 
istry. By  Edgar  F.  Smith,  Professor  of  Chemistry,  University  of  Pennsylvania, 
and  Dr.  H.  F.  Keller,  Professor  of  Chemistry,  Philadelphia  High  School.  Third 
Edition.     8vo.     Illustrated.  Cloth,  .60 

STARR.  The  Digestive  Organs  in  Childhood.  Second  Edition.  The  Diseases 
of  the  Digestive  Organs  in  Infancy  and  Childhood.  With  Chapters  on  the 
Investigation  of  Disease  and  the  Management  of  Children.  By  Louis  Starr, 
M.D.,  late  Clinical  Prof,  of  Diseases  of  Children  in  the  Hospital  of  the  University 
of  Penn'a;  Physician  to  the  Children's  Hospital,  Phila.  Second  Edition. 
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numerous  Wood  Engravings.     Crown  Octavo.  Cloth,  $2.00 

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24  P.  BLAKISTON,  SON  &-  CO:S 

STAMMER.  Chemical  Problems,  with  Explanations  and  Answers.  By  Karl 
Stammer.  Translated  from  the  Second  German  Edition,  by  Prof.  W.  S.  Hos- 
KiNSON,  A.M.,  Wittenberg  College,  Springfield,  Ohio.     i2mo.  Cloth.  ,50 

STARLING.  Elements  of  Human  Physiology.  By  Ernest  H.  Starling,  m.d. 
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etc.     With  100  Illustrations.      i2mo.     437  pages.  Cloth,  $1.00 

STEARNS.  Lectures  on  Mental  Diseases.  By  Henry  Putnam  Stearns,  m.d., 
Physician  Superintendent  at  the  Hartford  Retreat,  Lecturer  on  Mental  Diseases 
in  Yale  University,  Member  of  the  American  Medico-Psychological  Ass'n,  Hon- 
orary Member  of  the  Boston  Medico-Pyschological  Society.  With  a  Digest  of 
Laws  of  the  Various  States  Relating  to  Care  of  Insane.    Illustrated, 

Cloth,  $2.75;  Sheep,  $3.25 

STEVENSON  AND  MURPHY.    A  Treatise  on  Hygiene.    By  Various  Authors. 
Edited  by  Thomas  Stevenson,  m.d.,  f.r.c.p.,  Lecturer  on  Chemistry  and  Medi- 
cal Jurisprudence  at  Guy's   Hospital,  London,  etc.,  and  Shirley  F.  Murphy, 
Medical  Officer  of  Health  to  the  County  of  London.    In  Three  Octavo  Volumes. 
Vol.  L    With  Plates  and  Wood  Engravings.   Octavo.  Cloth,  $6.00 

Vol.  11.     With  Plates  and  Wood  Engravings.     Octavo.  Cloth,  $6.00 

Vol.  III.     Sanitary  Law.     Octavo.  Cloth,  $5.00 

^ ^Special  Circular  upon  application. 

STEWART'S  Compend  of  Pharmacy.  Based  upon  "  Remington's  Text-Book  of 
Pharmacy."  By  F.  E.  Stewart,  m.d.,  ph. g.,  Quiz  Master  in  Chem.  and  Theoreti- 
cal Pharmacy,  Phila.  College  of  Pharmacy;  Lect.  in  Pharmacology,  Jefferson 
Medical  College.  Fifth  Ed.  Revised  in  accordance  with  U.  S.  P.,  1890.  Com- 
plete tables  of  Metric  and  English  Weights  and  Measures.  ? Quiz- Compend? 
Series.  Cloth,  .80;  Interleaved  for  the  addition  of  notes,  $1.25 

STIRLING.  Outlines  of  Practical  Physiology.  Including  Chemical  and  Experi- 
mental Physiology,  with  Special  Reference  to  Practical  Medicine.  By  W.  Stir- 
ling, m.d.,  Sc.d.,  Professor  of  Physiology  and  Histology,  Owens  College,  Victoria 
University,  Manchester.  Examiner  in  Physiology,  Universities  of  Edinburgh 
and  London.     Third  Edition.     289  Illustrations.  Cloth,  $2.00 

Outlines  of  Practical  Histology.     368  Illustrations.     Second  Edition.     Re- 
vised and  Enlarged  with  new  Illustrations.     i2mo.  Cloth,  $2.00 

STRAHAN.  Extra-Uterine  Pregnancy.  The  Diagnosis  and  Treatment  of  Extra- 
Uterine  Pregnancy.  Being  the  Jenks  Prize  Essay  of  the  College  of  Physicians 
of  Philadelphia.  By  John  Strahan,  m.d.  (Univ.  of  Ireland),  late  Res.  Surgeon 
Belfast  Union  Infirmary  and  Fever  Hospital.     Octavo.  Cloth,  .75 

SWANZY.  Diseases  of  the  Eye  and  their  Treatment.  A  Handbook  for  Physi- 
cians and  Students.  By  Henry  R.  Swanzy,  a.m.,  m.b.,  f.r.c.s.i.,  Surgeon  to 
the  National  Eye  and  Ear  Infirmary  ;  Ophthalmic  Surgeon  to  the  Adelaide  Hos- 
pital, Dublin.  Fifth  Edition,  Thoroughly  Revised.  Edited  by  Louis  Werner, 
M.B.,  B.CH.  Enlarged.  166  Illustrations,  one  Plain  Plate,  and  a  Zephyr  Test 
Card.     i2mo.  Cloth,  $2.50;  Sheep,  I3.00 

STOHR.  Histology  and  Microscopical  Anatomy.  By  Dr.  Philipp  Stohr, 
Professor  in  the  University  of  Zurich.  Translated  and  Edited  by  Dr.  Alfred 
Schaper,  Demonstrator  of  Histology  and  Embryology,  Harvard  Medical  School, 
Boston.     260  Illustrations.  Preparing. 


MEDICAL  AND  SCIENTIFIC  PUBLIC  A  TIONS.  26 

SWAIN.  Surgical  Emergencies,  together  with  the  Emergencies  Attendant  on 
Parturition  and  the  Treatment  of  Poisoning.  A  Manual  for  the  Use  of  Student, 
Practitioner,  and  Head  Nurse.  By  William  Paul  Swain,  f.r.c.s.,  Surgeon  to 
the  South  Devon  and  East  Cornwall  Hospital,  England.  Fifth  Edition.  i2mo. 
Illustrated.  Nearly  Ready. 

SUTTON'S  Volumetric  Analysis.  A  Systematic  Handbook  for  the  Quantitative 
Estimation  of  Chemical  Substances  by  Measure,  Applied  to  Liquids,  Solids  and 
Gases.  By  Francis  Sutton,  f.c.s.  Seventh  Edition,  Revised  and  Enlarged, 
with  Illustrations.     8vo.  /«  Press. 

STMONDS.  Manual  of  Chemistry,  for  Medical  Students.  By  Brandreth 
SvMONDS,  A.M.,  M.D.,  Ass't  Physician  Roosevelt  Hospital, Out- Patient  Department; 
Attending  Physician  Northwestern  Dispensary,  New  York.  Second  Edition. 
i2mo.  Cloth,  $2.co 

TAFT'S  Operative  Dentistry.  A  Practical  Treatise  on  Operative  Dentistry.  By 
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lustrations.    8vo.  Cloth,  $3.00  ;  Leather,  $4.00 

Index  of  Dental  Periodical  Literature.    8vo.  Cloth,  $2.00 

TALBOT.  Irregularities  of  the  Teeth,  and  Their  Treatment.  By  Eugene  S. 
Talbot,  m.d..  Professor  of  Dental  Surgery  Woman's  Medical  College,  and 
Lecturer  on  Dental  Pathology  in  Rush  Medical  College,  Chicago.  Second  Edi- 
tion, Revised  and  Enlarged  by  about  100  pages.  Octavo.  234  Illustrations 
(169  of  which  are  original).     261  pages.  Cloth,  $3.cx) 

TANNER'S  Memoranda  of  Poisons  and  their  Antidotes  and  Tests.  By  Thos. 
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TAYLOR.  Practice  of  Medicine.  A  Manual.  By  Frederick  Taylor,  m.d., 
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TAYLOR  AND  WELLS.  Diseases  of  Children.  A  Manual  for  Students  and 
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Children,  Philadelphia  Polyclinic;  Assistant  Physician  to  the  Children's  Hospi- 
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cal College.     With  Illustrations.  In  Press. 

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THOMPSON.  Urinary  Organs.  Diseases  of  the  Urinary  Organs.  Containing  32 
Lectures.  By  Sir  Henry  Thompson,  f.r.c.s.,  Emeritus  Professor  of  Clinical  Sur- 
gery in  University  College.  Eighth  London  Edition.  121  Illustrations.  Octavo. 
470  pages.  Cloth,  $3.co 

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the  Use  of  Solvent  Remedies.     Third  Edition.        i6mo.  Cloth,  .75 

THORBURN.  Surgery  of  the  Spinal  Cord.  A  Contribution  to  the  study  of.  By 
William  Thorburn,  b.Sc.,  m.d.     Illustrated.     Octavo.  Cloth,  J4.00 

THORNTON.  The  Surgery  of  the  Kidneys.  By  John  Knowsley  Thornton, 
M.B.  Edin.     With  19  Illustrations.  Cloth,  $1.50 


26  P.  BLAKJSTON,  SQN  &^  CO.'S 

TOMES'  Dental  Anatomy.    A  Manual  of  Dental  Anatomy,  Human  and  Compara- 
tive.    By  C.  S.  Tomes,  d.d.s.     235  Illustrations.    4th  Ed.     i2mo.     Cloth,  $3.50 
Dental  Surgery.    A  System  of  Dental  Surgery.    By  John  Tomes,  f.r.s. 
Third  Edition,  Revised   and   Enlarged.      By  C.  S.  Tomes,  d.d.s.      With 
292  Illustrations.     i2mo.     772  pages.  Cloth,  $4.00 

TRANSACTIONS  of  the  Association  of  American  Physicians.  Vols.  I  and  11. 
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TREVES.  German-English  Medical  Dictionary.    By  Frederick  Treves,  f.r.c.s., 

assisted  by  Dr.  Hugo  Lang,  b.a.  (Munich).     i2mo.  )4  Russia,  $3.25 

Physical  Education,  Its  Effects,  Value,  Methods,  etc.  Cloth,  .75 

TRIMBLE.  Practical  and  Analytical  Chemistry.  By  Henry  Trimble,  ph.m.. 
Professor  of  Analytical  Chemistry  in  the  Philadelphia  College  of  Pharmacy. 
Fourth  Edition.     Illustrated.     8vo.  Cloth,  $1.50 

TTTKE.  Dictionary  of  Psychological  Medicine.  Giving  the  Definition,  Ety- 
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Symptoms,  Pathology,  and  Treatment  of  the  recognized  forms  of  Mental  Dis- 
orders, together  with  the  Law  of  Lunacy  in  Great  Britain  and  Ireland.  Edited  by 
D.  Hack  Tuke,  m.d.,ll.d..  Examiner  in  Mental  Physiology  in  the  University 
of  London.     Two  Volumes.     Octavo.  Cloth,  ;5 10.00 

TURNBTJLL'S  Artificial  Anaesthesia.  The  Advantages  and  Accidents  of  Artifi- 
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ministration ;  Considering  their  Relative  Risks ;  Tests  of  Purity ;  Treatment  of 
Asphyxia;  Spasms  of  the  Glottis;  Syncppe,  etc.  By  Laurence  Turnbull,  m.d., 
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vised and  Enlarged.    40  Illustrations.     i2mo.  Cloth,  $3.00 

TTTSON.  Veterinary  Pharmacopoeia,  including  the  outlines  of  Materia  Medica 
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inary College.  Fifth  Edition.  Revised  and  Edited  by  James  Bayne,  f.c.s.. 
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TYSON.    The  Practice  of  Medicine.    A  Text- Book  for  Physicians  and  Students, 

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MEDICAL  AND  SCIENTIFIC  PUBLICA  TIONS.  27 

VAN  NTJYS  on  The  Urine.  Chemical  Analysis  of  Healthy  and  Diseased  Urine, 
Qualitative  and  Quantitative.  By  T.  C.  Van  Nuys,  Professor  of  Chemistry 
Indiana  University.     39  Illustrations.     Octavo.  Cloth,  $1.00 

VIRCHOWS  Post-mortem  Examinations.  A  Description  and  Explanation  of  the 
Method  of  Performing  them  in  the  Dead  House  of  the  Berlin  Charite  Hospital, 
with  especial  reference  to  Medico-legal  Practice.  By  Prof.  Virchow.  Trans- 
lated by  Dr.  T.  P.  Smith.    Illustrated.    Third  Edition,  with  Additions.    Cloth,  .75 

VOSWINKEL.  Surgical  Nursing.  A  Manual  for  Nurses.  By  Bertha  M.  Vos- 
wiNKEL,  Graduate  Episcopal  Hospital,  Philadelphia,  Nurse  in  Charge  Children's 
Hospital,  Columbus,  O.    1 1 1  Illustrations.    i2mo.    168  pages.  Cloth,  $1.00 

WALSHAM.  Manual  of  Practical  Surgery.  For  Students  and  Physicians.  By 
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WARREN.  Compend  Dental  Pathology  and  Dental  Medicine.  Containing  all 
the  most  noteworthy  points  of  interest  to  the  Dental  Student  and  a  Chapter 
on  Emergencies.  By  Geo.  W.  Warren,  d.d.s.,  CHnical  Chief,  Penn'a  College 
of  Dental  Surgery,  Phila.  Second  Edition,  Enlarged.  Illustrated.  Beinf[  No. 
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to  the  London  Fever  Hospital,  and  Edward  W.  Goodall,  m.d.  (London), 
Medical  Superintendent  Easton  (Fever)  Hospital,  Homerton,  London,  etc. 
Illustrated  with  Charts,  Diagrams,  and  Plates.  In  Press. 

WATSON  on  Amputations  of  the  Extremities  and  Their  Complications.  By 
B.  A.  Watson,  m.d.     250  Illustrations.  Cloth,  $5.50 

Concussions.  An  Experimental  Study  of  Lesions  arising  from  Severe  Con- 
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Chemistry.)  By  Henry  Watts,  b.a.,  f.r.s.  With  Colored  Plate  of  Spectra 
and  other  Illustrations.     i2mo.     595  pages.  Cloth,  $2.00 

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"  From  such  a  standpoint  it  goes  without  saying  that  the  writer's  attitude  is  a  conservative 
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expressly  for  this  work.  It  has  all  the  conciseness  of  Druitt's  well  known  work,  and  the 
advantage  of  a  somewhat  more  extensive  description  of  certain  conditions  occurring  in  practical 
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?  Quiz-Compends  ?.  They  are  well  arranged,  full,  and  concise,  and  are  really  the  best  line  of  text- 
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BLAKISTON'S  ?QUIZ=COMPENDS? 

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49^  The  authors  have  had  large  experience  as  Quiz-Masters  and  attaches  of  colleges,  and  are  well 
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4S~  They  are  arranged  in  the  most  approved  form,  thorough  and  concise,  containing  over  600  fine  illustra- 
tions, inserted  wherever  they  could  be  used  to  advantage. 

49*  Can  be  used  by  students  o{  any  college. 

i^"  They  contain  information  nowhere  else  collected  in  a  such  a  condensed,  practical  shape. 

ILLUSTRATED  CIRCULAR  FREE. 

No.  1.  HUMAN  ANATOMY.  Fifth  Revised  and  Enlarged  Edition.  Including  Visceral  Anatomy.  Can 
be  used  with  either  Morris's  or  Gray's  Anatomy.  117  Illustrations  and  16  Lithographic  Plates  of  Nerves  and 
Arteries,  with  Explanatory  Tables,  etc.  By  Samuel  O.  L  Potter,  m.d..  Professor  of  the  Practice  oJ 
Medicine,  Cooper  Medical  College,  San  Francisco  ;  late  A.  A.  Surgeon,  U.  S.  Army. 

No.  2.  PRACTICE  OF  MEDICINE.  Part  I.  Fifth  Edition,  Revised.  Enlarged,  and  Improved.  By 
Dan'l  E.  Hughes,  m.d.,  Physician-in-Chief,  Philadelphia  Hospital,  late  Demonstrator  of  Clinical  Medi- 
cine, Jefferson  Medical  College,  Philadelphia. 

No.  3.  PRACTICE  OF  MEDICINE.  Part  II.  Fifth  Edition,  Revised,  Enlarged,  and  Improved.  Same 
author  as  No.  z. 

No.  4.  PHYSIOLOGY,  Seventh  Edition,  with  new  Illustrations  and  a  table  of  Physiological  Constants. 
Enlarged  and  Revised.  By  A.  P.  Bkubaker,  m.d..  Professor  of  Physiology  and  General  Pathology  in  the 
Pennsylvania  College  of  Dental  Surgery;  Demonstrator  of  Physiology,  Jefferson  Medical  College,  Phila- 
delphia. 

No.  5.  OBSTETRICS.  Fifth  Edition.  By  Henky  G.  Landis,  m.d.  Revised  and  Edited  by  Wm.  H. 
Wells,  m.d  ,  Assistant  Demonstrator  of  Obstetrics,  Jefferson  Medical  College,  Philadelphia.  Enlarged. 
47  Illustrations. 

No.  6.  MATERIA  MEDICA,  THERAPEUTICS,  AND  PRESCRIPTION  WRITING.  Sixth 
Revised  Edition  (U.  b.  P.  1890).  By  Samuel  O.  L  Pottkk,  m.d.  Professor  of  Practice,  Cooper  Medical 
College,  San  Franci.'ico  :  late  A    A.  Surgeon,  U.  S.  Army. 

No.  7.  GYN.ffiCOLOGY.  A  New  Book.  By  Wm  H.  Wells,  m.d..  Assistant  Denfonstrator  of  Obstetrics, 
Jefferson  College,  Philadelphia,     lilu-trated. 

No.  8.  DISEASES  OF  THE  EYE  AND  REFRACTION.  Second  Edition.  Including  Treatment  and 
Surgery.     By  L   Webstbk  Fox,  m  d.,  and  Gedkge  M.  Gould,  m.d.    With  39  Formulae  and  71  Illustrations. 

No.  9.  SURGERY,  Minor  Surgery,  and  Bandaging.  Fifth  Edition,  Enlarged  and  Improved.  By 
.  Orvillk  Horwitz,  B.S.,  M.D.,  Clinical  Professor  ot  Genito-Urinary  Surgery  and  Venereal  Diseases  in  Jef- 
ferson  Medical  College  ;  Surgeon  to  Philadelphia  Hospital,  etc.     W  ith  98  Formulae  and  71  Illustrations. 

No.  10.  MEDICAL  CHEMISTRY.  Fourth  Edition.  Including  Urinalysis,  Animal  Chemistry  Chemistry 
of  Milk,  Blood,  Tissues,  the  Secretions,  etc  By  Henkv  Lbffmann,  m.d..  Professor  of  Chemistry  in 
Pennsylvania  College  of  Dental  Surgery  and  in  the  Woman's  Medical  College,  Philadelphia. 

No.  II.  PHARMACY.  Fifth  Edition.  Based  upon  Prof.  Remington's  Text-Book  of  Pharmacy.  By  F. 
E.  Stewart,  m.d.,ph.g.,  late  Quiz-Master  in  Pharmacy  and  Chemistry,  Philadelphia  College  of  Pharmacy; 
Lecturer  at  Jefferson  Medical  College.     Carefully  revised  in  accordance  with  the  new  U.  S.  P. 

No.  12.  VETERINARY  ANATOMY  AND  PHYSIOLOGY.  Illustrated.  By  \yM.  R.  Ballou,  m.d.. 
Professor  of  Equine  Anatomy  at  New  York  College  of  Veterinary  Surgeons ;  Physician  to  Bellevue  Dis- 
pensary, etc.     Wiih  29  graphic  Illustrations. 

No.  13.  DENTAL  PATHOLOGY  AND  DENTAL  MEDICINE.  Second  Edition,  Illustrated.  Con- 
taining all  the  most  noteworthy  points  of  interest  to  the  Dental  Student  and  a  Section  on  Emergencies.  By 
Geo.  W.  Warren,  d.d  s.  ,  Chief  of  Clinical  Staff,  Pennsylvania  College  of  Dental  Surgery,  Philadelphia. 

No.  14.  DISEASES  OF  CHILDREN.  Colored  Plate.  By  Marcus  P.  Hatfield,  Professor  of  Dis- 
eases of  Children,  Chicago  Medical  College.     Second  Edition,  Enlarged. 

No.  15.  GENERAL  PATHOLOGY  AND  MORBID  ANATOMY.  91  Illustrations.  By  H.  New- 
berry Hall,  ph.g.,  m.d.,  Professor  of  Pathology  and  Medical  Chemistry,  Chicagu  Post-Graduate  Medical 
School :  Member  Surgical  Staff,  Illinois  Charitable  Eye  and  Ear  Infirmary  ;  Chief  of  Ear  Clinic,  Chicago 
Medical  College. 

No.  16.     DISEASES  OF  NOSE  AND  EAR.     Illustrated.     Same  Author  as  No.  15. 

Price,  each,  .80.       Interleaved,  for  taking  Notes,  $1.25. 

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The  Physicians  Visiting  List. 

(LINDSAY  &  BLAKISTON'S.) 

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In  order  to  improve  and  simplify  this  Visiting  List  we  have  done  away  with  the  two 
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for  writing  the  names,  stpd  added  to  the  special  memoranda  page  a  column  for  the 
"Amount"  of  the  weekly  visits  and  a  column  for  the  "Ledger  Page."  To  do  this  with- 
out increasing  the  bulk  or  the  price,  we  have  condensed  the  reading  matter  in  the  front 
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The  Lists  for  75  Patients  and  100  Patients  will  also  have  special  memoranda  page  as 
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be  mislaid. 

Before  making  these  changes  we  have  personally  consulted  a  number  of  physicians 
who  have  used  the  book  for  many  years,  and  have  takea  into  consideration  many  sugges- 
tions made  in  letters  from  all  parts  of  the  country. 


CONTENTS. 


PRELIMINARY  MATTER. — Calendar,  1 896-1897 — Table  of  Signs,  to  be  used  in  keeping  records — 
The  Metric  or  French  Decimal  System  of  Weights  and  Measures — Table  for  Converting  Apothecaries' 
Weights  and  Measures  into  Grams — Dose  Table,  giving  the  doses  of  official  and  unofficial  drugs  in  both 
the  Engli>h  and  Metric  Systems — Asphyxia  and  Apnea — Complete  Table  for  Calculating  the  Period  of 
Utero-Gestation — Comparison  of  Thermometers. 

VISITING  LIST. — Ruled  and  dated  pages  for  25, 50, 75,  and  too  patients  per  day  or  week,  with  blank  page 
opposite  each  on  which  is  an  amount  column,  column  for  ledger  page,  and  space  for  special  memoranda. 

SPECIAL  RECORDS  for  Obstetric  Engagements,  Deaths,  Births,  etc.,  with  special  pages  for  Addresses 
of  Patients,  Nurses,  etc.,  Accounts  Due,  Cash  Account,  and  General  Memoranda. 

# 

SIZES  AND    PRICES. 

REGULAR  EDITION,  as  Described  Above. 

BOUND   IN   STRONO   LEATHER  COVERS,  "WITH    POCKET  AND    PENCIL. 

For  25  Patients  weekly,  with  Special  Memoranda  Page, $100 

50        "  «'  "  "  '« I  25 

Li  <.  if  January  to  Tune    ")  ^  „^ 

CO        "  "  "  "  "        2  vols.  -(•;  ,     ^■'t-vu      r 2  00 

•'  (  |uly  to  December  J 

«  «  ««  «<  «        2>      1     /  January  to  June    1  2  00 

'5  •  "1^  July  X.O  December  J 

TOO        "             ««                «                        '<                "        2  vols  i  J^""^"^  ^°  J""^    \  2  2t; 

*°°  ^  ''°^^- 1  July  to  December  / ^  ^5 

PERPETUAL  EDITION,  without  Dates. 

No.  I.  Containing  space  for  over  1300  names,  with  blank  page  opposite  each  Visiting  List  page. 

Bound  in  Red  Leather  cover,  with  Pocket  and  Pencil, $1  25 

No.  2.  Same  as  No.  i.     Containing  space  for  2600  names,  with  blank  page  opposite, i  50 

MONTHLY  EDITION,  without  Dates. 

No.  I.  Bound,  Seal  leather,  without  Flap  or  Pencil,  gilt  edges, 75 

No.  2.  Bound,  Seal  leather,  with  Tucks,  Pencil,  etc.,  gilt  edges, i  00 


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Circular  and  sample  pages  upon  application. 

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UNIVERSITY  OF  CALIFORNIA  LIBRARY 
Los  Angeles 

This  book  is  DUE  on  the  last  date  stamped  below. 


» 


cj-n 


6\»!s;^ 


vam  J!1L26'86 

BIOMEOLIB 

JUL  2  6  1986 

REC'D 


Form  L9-Series  4939 


3  11 58  01112  1489 


A    000  414  495     2 


